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- ************************************************************
- * Prokaryotic-type peptide chain release factors signature *
- ************************************************************
-
- Peptide chain release factors (RFs) are required for the termination of
- protein biosynthesis. RFs bind to ribosomes that have encountered a stop codon
- at their decoding site. In prokaryotes there are at least two RFs that act in
- a codon specific manner [1]: RF-1 (gene prfA) mediates UAA and UAG-dependent
- termination while RF-2 (gene prfB) mediates UAA and UGA-dependent termination.
- RF-1 and RF-2 are structurally and evolutionary related proteins which have
- been shown [2] to make up a family that also contains the following proteins:
-
- - Yeast MRF1, a mitochondrial RF which recognizes the UAA and UAG codons.
- - Escherichia coli RF-H, a protein of unknown function.
-
- We use as a signature pattern a highly conserved region located in the central
- part of these proteins.
-
- -Consensus pattern: S-G-x-G-G-Q-H-V-N
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Note: RF-3 (gene prfC), the third bacterial release factor, does not belong
- to this family, it is related to GTP-binding elongation factors.
-
- -Expert(s) to contact by email: Tate W.
- biocwpt@otago.ac.nz
-
- -Last update: June 1994 / Text revised.
-
- [ 1] Craigen W.J., Lee C.C., Caskey C.T.
- Mol. Microbiol. 4:861-865(1990).
- [ 2] Pel H.J., Rep M., Grivell L.A.
- Nucleic Acids Res. 20:4423-4428(1992).
-