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- * Eukaryotic RNA polymerase II heptapeptide repeat *
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-
- RNA polymerase II (EC 2.7.7.6) [1,2] is one of the three forms of RNA
- polymerase that exist in eukaryotic nuclei. The C-terminal region of the
- largest subunit of this oligomeric enzyme consists of the tandem repeat of a
- conserved heptapeptide [3]. The number of repeats varies according to the
- species (for example: 17 in Plasmodium, 26 in yeast, 44 in Drosophila, and 52
- in mammals). The region containing these repeats is essential to the function
- of polymerase II. This repeated heptapeptide (called CT7n or CTD) is rich in
- hydroxyl groups. It probably projects out of the globular catalytic domain and
- may interact with the acidic activator domains of transcriptional regulatory
- proteins. It is also known to bind by intercalation to DNA. RNA polymerase II
- is activated by phosphorylation. The serine and threonine residues in the CT7n
- repeats are the target of such phosphorylation.
-
- -Consensus pattern: Y-[ST]-P-[ST]-S-P-[STANK]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Note: the consensus for the heptapeptide repeat is Y-S-P-T-S-P-S, but we have
- allowed variants in position 2, 4, and, 7 of the pattern so as to detect some
- of the imperfect repeats.
- -Note: protozoan parasites such Trypanosoma and Crithidia do not have a CT7n
- domain.
-
- -Last update: December 1991 / Text revised.
-
- [ 1] Woychik N.A., Young R.A.
- Trends Biochem. Sci. 15:347-350(1990).
- [ 2] Young R.A.
- Annu. Rev. Biochem. 60:689-715(1991).
- [ 3] Corden J.L.
- Trends Biochem. Sci. 15:383-387(1990).
-