home *** CD-ROM | disk | FTP | other *** search
- *************************************************************
- * Protein prenyltransferases alpha subunit repeat signature *
- *************************************************************
-
- Protein prenyltransferases catalyze the transfer of an isoprenyl moiety to a
- cysteine four residues from the C-terminus of several proteins. They are
- heterodimeric enzymes consisting of alpha and beta subunits. The alpha subunit
- is thought to participate in a stable complex with the isoprenyl substrate;
- the beta subunit binds the peptide substrate. Distinct protein
- prenyltransferases might share a common alpha subunit. Both the alpha and
- beta subunit show repetitive sequence motifs [1]. These repeats have distinct
- structural and functional implications and are unrelated to each other. Known
- protein prenyltransferase alpha subunits are:
-
- - Mammalian protein farnesyltransferase alpha subunit.
- - Yeast protein RAM2, a protein farnesyltransferase alpha subunit.
- - Yeast protein MAD2, a protein geranylgeranyltransferase alpha subunit.
-
- The conserved domain of the alpha subunit consists of about 34 amino acids and
- is repeated five times. It contains an invariant tryptophan possibly involved
- in heterodimerization with the conserved phenylalanines in the repeated
- domains of the beta subunits, via hydrophobic bonds. The signature pattern for
- this domain is centered on the invariant tryptophan.
-
- -Consensus pattern: [PSIAV]-x-[NDFV]-[NEQIY]-x-[LIVMAGP]-W-[NQSTHF]-[FYHQ]-
- [LIVMR]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: 13 where the pattern is found only
- once, whereas it is found five times in known protein prenyltransferase alpha
- subunits.
- -Last update: June 1994 / Text revised.
-
- [ 1] Boguski M.S., Murray A.W., Powers S.
- New Biol. 4:408-411(1992).
-