The isoprenylcysteine o-methyltransferase (EC 2.1.1.100) carries out carboxyl methylation of cleaved eukaryotic proteins that terminate in a CaaX motif. In Saccharomyces cerevisiae (Baker's yeast) this methylation is carried out by Ste14p, an integral endoplasmic reticulum membrane protein. Ste14p is the founding member of the isoprenylcysteine carboxyl methyltransferase (ICMT) family, whose members share significant sequence homology.[1]
ICMT | |||||||||
---|---|---|---|---|---|---|---|---|---|
Identifiers | |||||||||
Symbol | ICMT | ||||||||
Pfam | PF04140 | ||||||||
Pfam clan | CL0115 | ||||||||
InterPro | IPR007269 | ||||||||
OPM superfamily | 159 | ||||||||
OPM protein | 4a2n | ||||||||
|
protein-S-isoprenylcysteine O-methyltransferase | |||||||||
---|---|---|---|---|---|---|---|---|---|
Identifiers | |||||||||
EC no. | 2.1.1.100 | ||||||||
CAS no. | 130731-20-3 | ||||||||
Databases | |||||||||
IntEnz | IntEnz view | ||||||||
BRENDA | BRENDA entry | ||||||||
ExPASy | NiceZyme view | ||||||||
KEGG | KEGG entry | ||||||||
MetaCyc | metabolic pathway | ||||||||
PRIAM | profile | ||||||||
PDB structures | RCSB PDB PDBe PDBsum | ||||||||
Gene Ontology | AmiGO / QuickGO | ||||||||
|
The enzyme catalyzes the chemical reaction
Thus, the two substrates of this enzyme are S-adenosyl methionine and protein C-terminal S-farnesyl-L-cysteine, whereas its two products are S-adenosylhomocysteine and protein C-terminal S-farnesyl-L-cysteine methyl ester.