In vivo interactions between gene products involved in the final stages of molybdenum cofactor biosynthesis in Escherichia coli.
The final stages of bacterial molybdenum cofactor (Moco) biosynthesis correspond to molybdenum chelation and nucleotide attachment onto an unique and ubiquitous structure, the molybdopterin. Using a bacterial two-hybrid approach, here we report on the in vivo interactions between MogA, MoeA, MobA, and MobB implicated in several distinct although linked steps in Escherichia coli. Numerous interactions among these proteins have been identified. Somewhat surprisingly, MobB, a GTPase with a yet unclear function, interacts with MogA, MoeA, and MobA. Probing the effects of various mo. mutations on the interaction map allowed us (i) to distinguish Moco-sensitive interactants from insensitive ones involving MobB and (ii) to demonstrate that molybdopterin is a key molecule triggering or facilitating MogA-MoeA and MoeA-MobA interactions. These results suggest that, in vivo, molybdenum cofactor biosynthesis occurs on protein complexes rather than by the separate action of molybdenum cofactor biosynthetic proteins.
Magalon
Axel
A
Laboratoire de Chimie Bactérienne, Institut Biologie Structurale et Microbiologie, CNRS, 31 chemin Joseph Aiguier, 13402 Marseille cedex 09, France. magalon@ibsm.cnrs-mrs.fr
Frixon
Chantal
C
Pommier
Jeanine
J
Giordano
Gerard
G
Blasco
Francis
F
D003067:Coenzymes; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D008667:Metalloproteins / Q000096:biosynthesis* / Q000235:genetics; D015335:Molecular Probes; D000090006:Molybdenum Cofactors; D009154:Mutation; D011621:Pteridines
D003067:Coenzymes; D008667:Metalloproteins; D015335:Molecular Probes; D000090006:Molybdenum Cofactors; D011621:Pteridines; C022261:molybdopterin