The biosynthesis of a choline nucleotide by a cell-free extract from Streptococcus pneumoniae.
Choline, a component of the wall teichoic acid of Streptococcus pneumoniae, was converted to cytidine diphosphocholine via choline phosphate by enzymes which were identified in cell-free extracts of the pneumococcus. The first enzyme, choline kinase, was investigated in some detail. It appeared to have a pH optimum of 7.3 to 7.4 and was stimulated by Mg2+. Kinetic studies gave an apparent Michaelis constant (Km) for ATP of I mM, and for choline of 0.19 mM, with Vmax values of 3 nmol min-1 (mg protein)-1 and 0.5 nmol min-1 (mg protein)-1 respectively. The second enzyme, CDPcholine pyrophosphorylase was specific for CTP and had a requirement for Mg2+ with an optimum at 7 mM.
D002474:Cell-Free System; D002794:Choline / Q000031:analogs & derivatives* / Q000378:metabolism; D002797:Choline Kinase / Q000378:metabolism; D003566:Cytidine Diphosphate Choline / Q000096:biosynthesis*; D009713:Nucleotidyltransferases / Q000378:metabolism; D013296:Streptococcus pneumoniae / Q000201:enzymology / Q000378:metabolism*
D003566:Cytidine Diphosphate Choline; D002797:Choline Kinase; D009713:Nucleotidyltransferases; D002794:Choline