A direct sulfhydrylation pathway is used for methionine biosynthesis in Pseudomonas aeruginosa.

M Foglino, F Borne, M Bally, G Ball, J C Patte

Index: Microbiology 141 ( Pt 2) , 431-9, (1995)

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Abstract

The relationship between genes and enzymes in the methionine biosynthetic pathway has been studied in Pseudomonas aeruginosa. The first step is catalysed by an O-succinylhomoserine synthase, the product of the metA gene mapped at 20 min on the chromosome. The second step is achieved by direct sulfhydrylation, involving the enzyme encoded by a metZ gene that we have identified and sequenced, located at 40 min. Thus Pseudomonas appears to be the only organism so far described that uses O-succinylhomoserine as substrate for a direct sulfhydrylation. As in yeast, the two transsulfuration pathways between cysteine and homocysteine, with cystathionine as an intermediate, probably exist in parallel in this organism.