Identification and characterization of the 'missing' terminal enzyme for siroheme biosynthesis in α-proteobacteria.

ABSTRACT: It has recently been shown that the biosynthetic route for both the d1 -haem cofactor of dissimilatory cd1 nitrite reductases and haem, via the novel alternative-haem-synthesis pathway, involves siroheme as an intermediate, which was previously thought to occur only as a cofactor in assimilatory sulphite/nitrite reductases. In many denitrifiers (which require d1 -haem), the pathway to make siroheme remained to be identified. Here we identify and characterize a sirohydrochlorin-ferrochelatase from Paracoccus pantotrophus that catalyses the last step of siroheme synthesis. It is encoded by a gene annotated as cbiX that was previously assumed to be encoding a cobaltochelatase, acting on sirohydrochlorin. Expressing this chelatase from a plasmid restored the wild-type phenotype of an Escherich

SUBMITTER: Bali S 

PROVIDER: S-EPMC4063343 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature