hpr , a phosphate carrier protein of the streptococcal phosphotransferase system , is phosphorylated at the n-1 position of a single histidyl residue in a reaction requiring phosphoenolpyruvate ( p-eprv ) , mg2+ , and enzyme i ( p-eprv-hpr phosphotransferase , ec2.7.3.9 ) .
C0031727
phosphotransferase
C0034348
p-eprv