Faculty Collaboration Database

Cloning and sequence of cymA, a gene encoding a tetraheme cytochrome c required for reduction of iron(III), fumarate, and nitrate by Shewanella putrefaciens MR-1. J Bacteriol 1997 Feb;179(4):1143-52

Date

02/01/1997

Pubmed ID

9023196

Pubmed Central ID

PMC178810

DOI

10.1128/jb.179.4.1143-1152.1997

Scopus ID

2-s2.0-0031054309 (requires institutional sign-in at Scopus site)   236 Citations

Abstract

The cymA gene, which encodes a tetraheme cytochrome c, was cloned from Shewanella putrefaciens MR-1. This gene complemented a mutant which had a TnphoA insertion in cymA and which was deficient in the respiratory reduction of iron(III), nitrate, fumarate, and manganese(IV). The 561-bp nucleotide sequence of cymA encodes a protein of 187 amino acids with a predicted molecular mass of 20.8 kDa. No N-terminal signal sequence was readily apparent; consistent with this, a cytochrome with a size of 21 kDa was detected in the wild type but was absent in the insertional mutant. The cymA gene is transcribed into an mRNA; the major transcript was approximately 790 bases, suggesting that it is not part of a multicistronic operon. This RNA transcript was not detected in the cymA mutant. The CymA protein was found in the cytoplasmic membrane and soluble fraction of MR-1, and it shares partial amino acid sequence homology with multiheme c-type cytochromes from other bacteria. These cytochromes are ostensibly involved in the transfer of electrons from the cytoplasmic membrane to acceptors in the periplasm. The localization of the fumarate and iron(III) reductases to the periplasm and outer membrane of MR-1, respectively, suggests the possibility of a similar electron transfer role for CymA.

Author List

Myers CR, Myers JM

MESH terms used to index this publication - Major topics in bold

Amino Acid Sequence
Base Sequence
Cloning, Molecular
Cytochrome c Group
DNA Transposable Elements
Electron Transport
Ferric Compounds
Fumarates
Genes, Bacterial
Genetic Complementation Test
Gram-Negative Facultatively Anaerobic Rods
Molecular Sequence Data
Molecular Weight
Mutagenesis, Insertional
Nitrates
Open Reading Frames
Oxidation-Reduction
Sequence Homology, Amino Acid