Entry
Name
triphosphate---protein phosphotransferase;
diphosphate:microsomal-membrane-protein O-phosphotransferase (erroneous);
DiPPT (erroneous);
pyrophosphate:protein phosphotransferase (erroneous);
diphosphate---protein phosphotransferase (erroneous);
diphosphate:[microsomal-membrane-protein] O-phosphotransferase (erroneous)
Class
Transferases;
Transferring phosphorus-containing groups;
Other protein kinases
BRITE hierarchy
Sysname
triphosphate:[microsomal-membrane-protein] phosphotransferase
Reaction(IUBMB)
triphosphate + [microsomal-membrane protein] = diphosphate + phospho-[microsomal-membrane protein] [RN:
R04312 ]
Reaction(KEGG)
Substrate
triphosphate [CPD:
C00536 ];
microsomal-membrane protein [CPD:
C03788 ]
Product
diphosphate [CPD:
C00013 ];
phospho-[microsomal-membrane protein]
Comment
This enzyme was originally thought to use diphosphate as substrate [1] but this has since been disproved [2]. The activity is observed as the second part of a biphasic reaction after depletion of ATP. Tripolyphosphate is a contaminant of [gamma-32P]ATP.
History
EC 2.7.99.1 created 1983 as EC 2.7.1.104, transferred 2005 to EC 2.7.99.1
Reference
Authors
Lam KS, Kasper CB.
Title
Pyrophosphate:protein phosphotransferase: a membrane-bound enzyme of endoplasmic reticulum.
Journal
Reference
Authors
Tsutsui K.
Title
Tripolyphosphate is an alternative phosphodonor of the selective protein phosphorylation of liver microsomal membrane.
Journal
J Biol Chem 261:2645-53 (1986)
Other DBs
ExplorEnz - The Enzyme Database: 2.7.99.1
ExPASy - ENZYME nomenclature database: 2.7.99.1
LinkDB
All DBs