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%\usepackage[utf8x]{inputenc}    % For unicode character support
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\usepackage{setspace}           % For line height
\usepackage{lastpage}           % Needed for total page number
\usepackage{seqsplit}           % Splits long words.
%\usepackage{opensans}          % Can't make this work so far. Shame. Would be lovely.
\usepackage[normalem]{ulem}     % For underlining links
% Most of the following are not required for the majority
% of cheat sheets but are needed for some symbol support.
\usepackage{amsmath}            % Symbols
\usepackage{MnSymbol}           % Symbols
\usepackage{wasysym}            % Symbols
%\usepackage[english,german,french,spanish,italian]{babel}              % Languages

% Document Info
\author{ilsccsonoa (holscassidy)}
\pdfinfo{
  /Title (transcription.pdf)
  /Creator (Cheatography)
  /Author (ilsccsonoa (holscassidy))
  /Subject (transcription Cheat Sheet)
}

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% Header and Footer
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\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
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    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
    }
\end{tabulary}
\columnbreak
\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{transcription Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{ilsccsonoa (holscassidy)} via \textcolor{DarkBackground}{\uline{cheatography.com/185549/cs/39027/}}}
\end{tabulary}
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\fancyfoot[L]{ \footnotesize
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{LL}
  \SetRowColor{FootBackground}
  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}ilsccsonoa (holscassidy) \\
  \uline{cheatography.com/holscassidy} \\
  \end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Not Yet Published.\\
   Updated 1st June, 2023.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
  \SetRowColor{white}
  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
\end{tabulary}
\end{multicols}}




\begin{document}
\raggedright
\raggedcolumns

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% www.emerson.emory.edu/services/latex/latex_169.html
\footnotesize % Small font.

\begin{multicols*}{3}

\begin{tabularx}{5.377cm}{x{1.94103 cm} x{3.03597 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{nucleotide \& nucleic acids}}  \tn
% Row 0
\SetRowColor{LightBackground}
nucleotide & sugar + N base + phosphate backbone \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
nucleoside & \textasciicircum{} - phosphate \tn 
% Row Count 3 (+ 1)
% Row 2
\SetRowColor{LightBackground}
nucleotide functions & energy for metabolism (ATP) \tn 
% Row Count 5 (+ 2)
% Row 3
\SetRowColor{white}
 & enzyme cofactors (NAD+) \tn 
% Row Count 6 (+ 1)
% Row 4
\SetRowColor{LightBackground}
 & signal transduction (cAMP) \tn 
% Row Count 8 (+ 2)
% Row 5
\SetRowColor{white}
nucleic acid functions & storage of DNA \tn 
% Row Count 10 (+ 2)
% Row 6
\SetRowColor{LightBackground}
 & transmission of DNA \tn 
% Row Count 11 (+ 1)
% Row 7
\SetRowColor{white}
 & processing of ribozymes \tn 
% Row Count 12 (+ 1)
% Row 8
\SetRowColor{LightBackground}
 & protein synthesis \tn 
% Row Count 13 (+ 1)
% Row 9
\SetRowColor{white}
 & regulation of expression \tn 
% Row Count 14 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{5.377cm}}{DNA \& RNA are polymers of nucleotide subunits which are linked by phosphodiester bonds}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{DNA structure}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{two chains of nucleotides coiled around each other in a right-handed double helix} \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{sugar-phosphate backbones of two strands spiral around outside of helix} \tn 
% Row Count 4 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{N bases extend into centre at right angles to the acids of helix} \tn 
% Row Count 6 (+ 2)
% Row 3
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{adenine forms 2 H bonds with thymine} \tn 
% Row Count 7 (+ 1)
% Row 4
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{cytosine forms 3 H bonds with guanine} \tn 
% Row Count 8 (+ 1)
% Row 5
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{opposite polarity of two strands} \tn 
% Row Count 9 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{p{0.59501 cm} p{0.86963 cm} x{3.11236 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{3}{x{5.377cm}}{\bf\textcolor{white}{RNA types}}  \tn
% Row 0
\SetRowColor{LightBackground}
rRNA & 80\% & 120 -5070 nucleotides \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
tRNA & 15\% & 75 nucleotides \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
mRNA & varies & varies \tn 
% Row Count 3 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}---}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{1.59264 cm} x{3.38436 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{RNA molecules}}  \tn
% Row 0
\SetRowColor{LightBackground}
mRNA & intermediates that carry genetic information from DNA to ribosomes \tn 
% Row Count 3 (+ 3)
% Row 1
\SetRowColor{white}
tRNA & adaptors between amino acids \& codons in mRNA \tn 
% Row Count 5 (+ 2)
% Row 2
\SetRowColor{LightBackground}
rRNA & structural \& catalytic components of ribosomes \tn 
% Row Count 7 (+ 2)
% Row 3
\SetRowColor{white}
siRNA & RNA interference \tn 
% Row Count 8 (+ 1)
% Row 4
\SetRowColor{LightBackground}
long non-coding RNA & transcription \tn 
% Row Count 10 (+ 2)
% Row 5
\SetRowColor{white}
microRNAs & RNA interference \tn 
% Row Count 11 (+ 1)
% Row 6
\SetRowColor{LightBackground}
ribozymes & RNA enzymes \tn 
% Row Count 12 (+ 1)
% Row 7
\SetRowColor{white}
small nuclear RNAs & structural components of spliceosomes \tn 
% Row Count 14 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{5.377cm}}{tRNA -\textgreater{} ribozymes are non protein-coding \newline siRNA -\textgreater{} ribozymes are regulatory}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{RNA structure}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{intrinsically single stranded} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{unable to form B-form helix due to bulky 2'-OH : when helical, RNA adopts A-form geometry, deep \& narrow major groove, wide minor groove} \tn 
% Row Count 4 (+ 3)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{secondary structure observed in rRNA \& tRNA, \& assumed to be in mRNA} \tn 
% Row Count 6 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{mRNA carries instructions for building a protein, eukaryotic mRNA is capped, polyA tail is not coding \& is added after transcription to stabilise mRNA - its removal degrades RNA \& inhibits translation}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{rRNA}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{makes up ribosomes} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{ribosomes are protein factories in large macromolecular assemblies, composed of many proteins rRNA molecules} \tn 
% Row Count 4 (+ 3)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{nucleolus is site of rRNA synthesis \& ribosome assembly} \tn 
% Row Count 6 (+ 2)
% Row 3
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{ribosomal components are commonly designated by their 'S' values = rate of sedimentation in an ultacentrifuge} \tn 
% Row Count 9 (+ 3)
% Row 4
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{although 18s \& 28s rRNAs of the eukaryotic ribosome contain many extra nucleotides not present in their bacterial counterparts, these nucleotides are present as multiple insertions that form extra domains \& leave basic structure of each rRNA largely unchanged} \tn 
% Row Count 15 (+ 6)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{transfer RNA is an intermediary between nucleic acid \& protein worlds, acts as a translator}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{2.4885 cm} x{2.4885 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{transcription in eukaryotes}}  \tn
% Row 0
\SetRowColor{LightBackground}
RNA polymerase I & Synthesises pre-ribosomal RNA (precursor for 28S, 18S, and 5.8 rRNAs) \tn 
% Row Count 4 (+ 4)
% Row 1
\SetRowColor{white}
RNA polymerase II & Responsible for synthesis of mRNA \tn 
% Row Count 6 (+ 2)
% Row 2
\SetRowColor{LightBackground}
RNA polymerase III & Makes tRNAs and some small RNA products \tn 
% Row Count 8 (+ 2)
% Row 3
\SetRowColor{white}
assembly of RNA polymerase & initiated by interaction of  TATA-binding protein (TBP) with the promoter, two TF's bind (IIA \& IIB) ,TFIIE and TFIIH bind: TFIIF binds to RNA Pol and targets it to the promoter, TFIIE  thought to be involved in DNA melting, Helicase activity in TFIIH unwinds DNA at the promoter \tn 
% Row Count 23 (+ 15)
% Row 4
\SetRowColor{LightBackground}
RNA strand initiation \& promoter clearance & Kinase activity in TFIIH phosphorylates the polymerase allowing the latter to escape the promoter, Initially 60-70 RNA nucleotides are synthesised, Then TFIIE \& TFIIH are released \tn 
% Row Count 32 (+ 9)
\end{tabularx}
\par\addvspace{1.3em}

\vfill
\columnbreak
\begin{tabularx}{5.377cm}{x{2.4885 cm} x{2.4885 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{transcription in eukaryotes (cont)}}  \tn
% Row 5
\SetRowColor{LightBackground}
elongation, termination \& release & TFIIF remains attached to RNA Pol II,  Elongation factors help efficiency, EF stop pausing and regulate \seqsplit{post-transcriptional} processing, phosphate removed at termination \tn 
% Row Count 9 (+ 9)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{RNA processing}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{Almost all newly synthesised RNA molecules (primary transcripts) are processed to some degree in eukaryotic cells} \tn 
% Row Count 3 (+ 3)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{The 5'-end is capped with methylguanosine} \tn 
% Row Count 4 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{Introns are spliced out} \tn 
% Row Count 5 (+ 1)
% Row 3
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{Poly-A tail is built at the 3' end - it probably protects 3' end from enzymatic destruction. However some bacteria acquire Poly A tails but these promote destruction.} \tn 
% Row Count 9 (+ 4)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{capping of 5' of mRNA}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{protects mRNA from 5'exonuclease degradation} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{Cap is 7-methylguanosine linked to 5' end of mRNA} \tn 
% Row Count 3 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{Formed by condensation of GTP with 5' end of mRNA} \tn 
% Row Count 5 (+ 2)
% Row 3
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{Guanine is then methylated} \tn 
% Row Count 6 (+ 1)
% Row 4
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{Occurs early in transcription} \tn 
% Row Count 7 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{capping enzymes are tethered to the c-terminal domain of polymerase II}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{placing poly (A) tail on mRNA}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{Pol II synthesises RNA up to and beyond the highly conserved seq: (5′)AAUAAA} \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{An endonuclease cleavage signal seq is bound by an enzyme complex} \tn 
% Row Count 4 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{The RNA is cleaved by the endonuclease at a point 10-30 nucleotides 3′ to (downstream of) the sequence AAUAAA} \tn 
% Row Count 7 (+ 3)
% Row 3
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{The polyadenylate polymerase synthesises a poly(A) tail} \tn 
% Row Count 9 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{transcription \& RNA processing}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{the central dogma of biology is that information stored in DNA is transferred to RNA molecules during transcription \& to proteins during translation. information stored in the nucleotide sequences of genes is translated into the aa seqs of proteins through unstable intermediaries (mRNAs). the mRNA codons on mRNA are translated into an aa seq by the ribosomes} \tn 
% Row Count 8 (+ 8)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{in eukaryotes, the primary transcript is pre-mRNA. it is modified at both ends \& introns are removed to produce mRNA. it is then exported to cytoplasm for translation by ribosomes.} \tn 
% Row Count 12 (+ 4)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{in RNA synthesis, the precursors are ribonucleoside triphosphates, only 1 strand of DNA is used as template \& RNA chains can be initiated de novo (without primer). RNA molecule will be complementary to DNA antisense (template) strand \& identical to DNA sense (non-template) strand). catalysed by RNA polymerases \& proceeds in 5' to 3' direction} \tn 
% Row Count 19 (+ 7)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{transcription vs DNA replication}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{RNA does not remain H-bonded to DNA post-synthesis} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{RNA molecules are selective copies of shorter DNA segments} \tn 
% Row Count 3 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{both employ polymerases - to make phosphodiester linkages} \tn 
% Row Count 5 (+ 2)
% Row 3
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{DNA is unwound ahead of synthesis} \tn 
% Row Count 6 (+ 1)
% Row 4
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{similar building blocks} \tn 
% Row Count 7 (+ 1)
% Row 5
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{RNA polymerase does not need a primer} \tn 
% Row Count 8 (+ 1)
% Row 6
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{DNA in a human chromosome can be up to 250 million bases whilst most RNA molecules are a few thousand bases in length.} \tn 
% Row Count 11 (+ 3)
% Row 7
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{RNA polymerase makes an error 1 x 104 nucleotides compared to 1 x10 7 for DNA polymerase. As RNA is temporary it is not so critical. Still RNA polymerase has a proof reading mechanism.} \tn 
% Row Count 15 (+ 4)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{the 'transcription bubble' - because of unwinding \& rewinding there are positive supercoils ahead of the bubble \& negative behind. topoisomerases deal with positive supercoils \& regulate negative ones.}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{2.04057 cm} x{2.93643 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{transcription in prokaryotes}}  \tn
% Row 0
\SetRowColor{LightBackground}
stages & 1. RNA chain initiation, 2. RNA chain elongation, 3. RNA chain termination \tn 
% Row Count 4 (+ 4)
% Row 1
\SetRowColor{white}
e.coli RNA polymerase & core enzyme = \seqsplit{alpha2-beta-beta'-omega} \tn 
% Row Count 6 (+ 2)
% Row 2
\SetRowColor{LightBackground}
 & holoenzyme = \seqsplit{alpha2-beta-beta'-omega-sigma} \tn 
% Row Count 8 (+ 2)
% Row 3
\SetRowColor{white}
 & alpha = assembly of the tetrameric core \tn 
% Row Count 10 (+ 2)
% Row 4
\SetRowColor{LightBackground}
 & beta = ribonucleoside triphosphate binding site \tn 
% Row Count 13 (+ 3)
% Row 5
\SetRowColor{white}
 & beta' = DNA template binding region \tn 
% Row Count 15 (+ 2)
% Row 6
\SetRowColor{LightBackground}
 & sigma = initiation of transcription \tn 
% Row Count 17 (+ 2)
% Row 7
\SetRowColor{white}
promoters & must be \textgreater{}12 bp in e.coli to avoid occurrence by chance, have only small conservation in sequence \tn 
% Row Count 22 (+ 5)
% Row 8
\SetRowColor{LightBackground}
 & Startpoint, -10 sequence (Pribnow box), -35 sequence and,  the 17 nucl spacer seq between -10 \& -35 seqs \tn 
% Row Count 27 (+ 5)
% Row 9
\SetRowColor{white}
 & 70 bases in length before start point \& 30 after. \tn 
% Row Count 30 (+ 3)
\end{tabularx}
\par\addvspace{1.3em}

\vfill
\columnbreak
\begin{tabularx}{5.377cm}{x{2.04057 cm} x{2.93643 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{transcription in prokaryotes (cont)}}  \tn
% Row 10
\SetRowColor{LightBackground}
transcription unit numbering & initiation site is +1 \tn 
% Row Count 2 (+ 2)
% Row 11
\SetRowColor{white}
 & Bases preceding the initiation site are given minus (–) prefixes and are referred to as upstream sequences \tn 
% Row Count 7 (+ 5)
% Row 12
\SetRowColor{LightBackground}
 & Bases following the initiation site are given plus (+) prefixes and are referred to as downstream sequences \tn 
% Row Count 12 (+ 5)
% Row 13
\SetRowColor{white}
1. binding \& initiation & Binding of RNA polymerase holoenzyme to a promoter region in DNA \tn 
% Row Count 15 (+ 3)
% Row 14
\SetRowColor{LightBackground}
 & Localised unwinding of both DNA strands (around -10 region) by RNA polymerase to provide a single-stranded template \tn 
% Row Count 20 (+ 5)
% Row 15
\SetRowColor{white}
 & Formation of phosphodiester bonds between the first few ribonucleotides in the nascent RNA chain \tn 
% Row Count 25 (+ 5)
% Row 16
\SetRowColor{LightBackground}
 & Conformational change in enzyme, promoter is cleared - sigma factor released \tn 
% Row Count 29 (+ 4)
% Row 17
\SetRowColor{white}
 & Nus A protein binds instead, ready for elongation - 'antitermination complex' \tn 
% Row Count 33 (+ 4)
\end{tabularx}
\par\addvspace{1.3em}

\vfill
\columnbreak
\begin{tabularx}{5.377cm}{x{2.04057 cm} x{2.93643 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{transcription in prokaryotes (cont)}}  \tn
% Row 18
\SetRowColor{LightBackground}
sigma cycle & RNA polymerase, guided by a bound sigma subunit, binds to DNA at a promoter sequence. Once RNA synthesis is initiated, the sigma subunit dissociates stochastically and is replaced by NusA. When RNA polymerase reaches a terminator sequence, RNA synthesis halts, NusA dissociates from the polymerase, and the RNA polymerase dissociates from the DNA. The free polymerase can, in principle, bind any sigma subunit. The type bound determines the promoter to which the RNA polymerase will bind in the next round of synthesis. \tn 
% Row Count 23 (+ 23)
% Row 19
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2. elongation & RNA polymerase is bound to DNA \& is covalently extending the RNA chain, moves downstream. \tn 
% Row Count 27 (+ 4)
% Row 20
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 & Transcription bubble is about 18 nucleotides pairs and about 40 bases are added per second.  Only about 3 bases are base paired at any moment in time. \tn 
% Row Count 34 (+ 7)
\end{tabularx}
\par\addvspace{1.3em}

\vfill
\columnbreak
\begin{tabularx}{5.377cm}{x{2.04057 cm} x{2.93643 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{transcription in prokaryotes (cont)}}  \tn
% Row 21
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3. termination & RNA polymerase transcribes until it meets a terminator, Transcription then stops \& the RNA product disassociates from the DNA template, Many terminators are hairpin forming sequences \tn 
% Row Count 8 (+ 8)
% Row 22
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 & Rho-dependent terminators — require a protein factor \tn 
% Row Count 11 (+ 3)
% Row 23
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 & Rho-independent terminators — do not require protein factor \tn 
% Row Count 14 (+ 3)
% Row 24
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rho-independent termination & G-C rich stem, 7-9 bases after loop is U-run, U-DNA pairing is very weak allows dissociation \tn 
% Row Count 18 (+ 4)
% Row 25
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rho-dependent termination & (rho factor) 46-kD protein, active as a hexamer, Seqs for the few Rho terminators are 50-90bp, Rho binds to RNA \tn 
% Row Count 23 (+ 5)
% Row 26
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 & (hot pursuit model) - It binds to RNA tail and moves along transcript until it catches the polymerase, Rho has helicase activity causing RNA-DNA to separate \tn 
% Row Count 30 (+ 7)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{introns}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{- non-coding seqs located between coding sequences \newline % Row Count 2 (+ 2)
- removed from the pre-mRNA and are not present in the mRNA \newline % Row Count 4 (+ 2)
- Exons (both coding and non-coding sequences) are composed of the seqs that remain in the mature mRNA after splicing \newline % Row Count 7 (+ 3)
- Introns are variable in size and may be very large% Row Count 9 (+ 2)
} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}


% That's all folks
\end{multicols*}

\end{document}