The biogenesis of c‐type cytochromes in Escherichia coli requires a membrane‐bound protein, DipZ, with a protein disulphide isomerase‐like domain
- 1 March 1995
- journal article
- Published by Wiley in Molecular Microbiology
- Vol. 15 (6), 1139-1150
- https://doi.org/10.1111/j.1365-2958.1995.tb02287.x
Abstract
A mutant of Escherichia coli K-12, JCB606, which lacks all five c-type cytochromes synthesized during anaerobic growth in the presence of nitrite or trimethylamine-N-oxide (TMAO), was totally defective in Nrf activity and also partially defective in TMAO reductase activity. The mutation in strain JCB606 was shown to affect expression of the tor operon, which contributes almost equally with the products of the dms operon to the rate of TMAO reduction by bacteria during anaerobic growth in the presence of TMAO. The mutation in strain JCB606, dipZ, was mapped by P1 transduction close to the mel operon at co-ordinate 4425 on the E. coli chromosome, the gene order being nrf-fdhF-mel-dipZ-ampC. Recombinant plasmids that restored Nrf activity to test-tube cultures of the mutant were isolated from a cosmid library. A 2.7 kb EcoRV-SmaI fragment (co-ordinates 4443 to 4446 kb on the physical map of the E. coli chromosome) was found potentially to encode three genes arranged in at least two operons. The second gene, dipZ, was sufficient to complement the JCB606 mutation. The translated DNA sequence predicts that DipZ is a 53 kDa integral membrane protein with a 37 kDa N-terminal domain including at least six membrane-spanning helices and a 16 kDa carboxy-terminal hydrophilic domain which includes a protein disulphide isomerase-like motif. It is suggested that DipZ is essential for maintaining cytochrome c apoproteins in the correct conformations for the covalent attachment of haem groups to the appropriate pairs of cysteine residues.Keywords
This publication has 51 references indexed in Scilit:
- Specific thiol compounds complement deficiency in c‐type cytochrome biogenesis in Escherichia coli carrying a mutation in a membrane‐bound disulphide isomerase‐like proteinFEBS Letters, 1994
- A mutation blocking the formation of membrane or periplasmic endogenous and exogenous c‐type cytochromes in Escherichia coli permits the cytoplasmic formation of Hydrogenobacter thermophilus holo cytochrome c552FEBS Letters, 1994
- TMAO anaerobic respiration in Escherichia coli: involvement of the tor operonMolecular Microbiology, 1994
- Regulation and sequence of the structural gene for cytochrome C552 from Escherichia coli: not a hexahaem but a 50kDa tetrahaem nitrite reductaseMolecular Microbiology, 1993
- Transcriptional control, translation and function of the products of the five open reading frames of the Escherichia coli nir operonMolecular Microbiology, 1992
- Membrane protein structure prediction: Hydrophobicity analysis and the positive-inside ruleJournal of Molecular Biology, 1992
- Precise physical mapping of theEscherichia coli pheU transcription unitFEBS Letters, 1991
- Location and sequence of the promoter of the gene for the NADH-dependent nitrite reductase of Escherichia coli and its regulation by oxygen, the Fnr protein and nitriteJournal of Molecular Biology, 1987
- Analysis of gene control signals by DNA fusion and cloning in Escherichia coliJournal of Molecular Biology, 1980
- The participation of cytochromes in the reduction of trimethylamine N-oxide by Escherichia coli.NIPPON SUISAN GAKKAISHI, 1978