Involvement of chlA, E, M, and N loci in Escherichia coli molybdopterin biosynthesis.

Journal Article (Journal Article)

All molybdenum enzymes except nitrogenase contain a common molybdenum cofactor, whose organic moiety is a novel pterin called molybdopterin (MPT). To assist in elucidating the biosynthetic pathway of MPT, two MPT-deficient mutants of Escherichia coli K-12 were isolated. They lacked activities of the molybdenum enzymes nitrate reductase and formate dehydrogenase, did not reconstitute apo nitrate reductase from a Neurospora crassa nit-1 strain, and did not yield form A, a derivative of MPT. By P1 mapping, these two mutations mapped to chlA and chlE, loci previously postulated but never definitely shown to be involved in MPT biosynthesis. The two new mutations are in different genetic complementation groups from previously isolated chlA and chlE mutations and have been designated as chlM and chlN (closely linked to chlA and chlE, respectively). The reported presence of Mo cofactor activity in the chlA1 strain is shown to be due to in vitro synthesis of MPT through complementation between a trypsin-sensitive macromolecule from the chlA1 strain and a low-molecular-weight compound from the nit-l strain.

Full Text

Duke Authors

Cited Authors

  • Johnson, ME; Rajagopalan, KV

Published Date

  • January 1987

Published In

Volume / Issue

  • 169 / 1

Start / End Page

  • 117 - 125

PubMed ID

  • 2947896

Pubmed Central ID

  • PMC211742

International Standard Serial Number (ISSN)

  • 0021-9193

Digital Object Identifier (DOI)

  • 10.1128/jb.169.1.117-125.1987


  • eng

Conference Location

  • United States