The Escherichia coli cysG gene encodes S-adenosylmethionine-dependent uroporphyrinogen III methylase.
The Escherichia coli cysG gene was successfully subcloned and over-expressed to produce a 52 kDa protein that was purified to homogeneity. This protein was shown to catalyse the S-adenosylmethionine-dependent methylation of uroporphyrinogen III to give a product identified as sirohydrochlorin on the basis of its absorption spectra, incorporation of 14C label from S-adenosyl[Me-14C]methionine and mass and 1H-n.m.r. spectra of its octamethyl ester. Further confirmation of the structure was obtained from a 14C-n.m.r. spectrum of the methyl ester produced by incubation of the methylase with uroporphyrinogen III, derived from [4.6-13C2]porphobilinogen, and S-adenosyl[Me-13C]methionine.
Department of Chemistry, Texas A & M University, College Station 77843.
M J
MJ
Warren
C A
CA
Roessner
P J
PJ
Santander
A I
AI
Scott
D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D002384:Catalysis; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics*; D015870:Gene Expression; D005798:Genes, Bacterial; D006418:Heme / Q000031:analogs & derivatives / Q000096:biosynthesis; D008780:Methyltransferases / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids; D013056:Spectrophotometry, Ultraviolet
D001426:Bacterial Proteins; D006418:Heme; C009272:siroheme; D008780:Methyltransferases; C060508:uroporphyrin-III C-methyltransferase