FIG 1.

Constructed sulfur amino acid metabolism and the linked metabolic network in Streptomyces griseus. Corresponding to the conventional name shown, the identified S. griseus ORF and its product are as follows: (1) sgr6646, homoserine O-acetyltransferase; (2) sgr6647, O-acetylhomoserine sulfhydrylase; (3) sgr2579, cystathionine-γ-synthase (CGS); (4) sgr3417, type II cystathionine-β-lyase (CBL); (5) sgr5847, B₁₂-dependent methionine synthase; (6) sgr1212, B₁₂-independent methionine synthase; (7) sgr6058, S-adenosylmethionine (SAM) synthetase; (8) sgr4513, S-adenosylhomocysteine (SAH) hydrolase; (9) sgr4452, cystathionine-β-synthase (CBS); and (10) sgr3660, cystathionine-γ-lyase (CGL). The abmD gene product is proposed to be a critical link between sulfur amino acid metabolism and ABM biosynthesis.