Updating the rna polymerase ctd
The two alleles denoted as LETHAL were those for which no haploid progeny were recovered after sporulation of heterozygous diploids.
( alleles in which the alanine filler between the minimized decapeptide repeats is shortened or in which P3A and S5A mutations are installed in the same heptad or different heptads of the diheptad repeat.
However, there were differences in the growth of the diheptad spacer mutants at low temperatures, whereby the (YSAPTSPSYSPTSPS) To query the requirements within the diheptad repeat, we installed blocks of two, three, four, or five alanines in lieu of the native amino acids at the distal end of each diheptad unit.
Although phosphorylation of Ser2 (Ser2P) and Ser5 (Ser5P) residues has been described as being essential for the expression of most pol II-transcribed genes, recent findings highlight gene-specific effects of newly discovered CTD modifications.
Here, we incorporate these latest findings in an updated review of the currently known elements that contribute to the CTD code and how it is recognized by proteins involved in transcription and RNA maturation.
The instantaneous primary structure of the CTD provides informational cues about the state of the transcription machinery—a CTD code—that is “read” by CTD receptor proteins (3).
Whereas one may gain important insights to CTD coding principles by probing biochemically and structurally how individual receptor proteins recognize the CTD, it is technically impossible with present crude methods (and perhaps conceptually unattainable the ensemble of proteins that are simultaneously engaged on the CTD.