Distribution and properties of the genes encoding the biosynthesis of the bacterial cofactor, pyrroloquinoline quinone.
Pyrroloquinoline quinone (PQQ) is a small, redox active molecule that serves as a cofactor for several bacterial dehydrogenases, introducing pathways for carbon utilization that confer a growth advantage. Early studies had implicated a ribosomally translated peptide as the substrate for PQQ production. This study presents a sequence- and structure-based analysis of the components of the pqq operon. We find the necessary components for PQQ production are present in 126 prokaryotes, most of which are Gram-negative and a number of which are pathogens. A total of five gene products, PqqA, PqqB, PqqC, PqqD, and PqqE, are identified as being obligatory for PQQ production. Three of the gene products in the pqq operon, PqqB, PqqC, and PqqE, are members of large protein superfamilies. By combining evolutionary conservation patterns with information from three-dimensional structures, we are able to differentiate the gene products involved in PQQ biosynthesis from those with divergent functions. The observed persistence of a conserved gene order within analyzed operons strongly suggests a role for protein-protein interactions in the course of cofactor biosynthesis. These studies propose previously unidentified roles for several of the gene products, as well as identifying possible new targets for antibiotic design and application.
Department of Chemistry, University of California, Berkeley, California 94720, United States.
Yao-Qing
YQ
Shen
Florence
F
Bonnot
Erin M
EM
Imsand
Jordan M
JM
RoseFigura
Kimmen
K
Sjölander
Judith P
JP
Klinman
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D005798:Genes, Bacterial; D007711:Klebsiella pneumoniae / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009876:Operon; D045542:PQQ Cofactor / Q000096:biosynthesis* / Q000235:genetics*; D010802:Phylogeny; D011487:Protein Conformation
D001426:Bacterial Proteins; D045542:PQQ Cofactor