Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2008-1-25
pubmed:abstractText
Bradyrhizobium japonicum cytochrome c(550), encoded by cycA, has been previously suggested to play a role in denitrification, the respiratory reduction of nitrate to dinitrogen. However, the exact role of this cytochrome in the denitrification process is unknown. This study shows that cytochrome c(550) is involved in electron transfer to the copper-containing nitrite reductase of B. japonicum, as revealed by the inability of a cycA mutant strain to consume nitrite and, consequently, to grow under denitrifying conditions with nitrite as the electron acceptor. Mutation of cycA had no apparent effect on methylviologen-dependent nitrite reductase activity. However, succinate-dependent nitrite reduction was largely inhibited, suggesting that c(550) is the in vivo electron donor to copper-containing nitrite reductase. In addition, this study demonstrates that a cytochrome c(550) mutation has a negative effect on expression of the periplasmic nitrate reductase. This phenotype can be rescued by extending the growth period of the cells. A model is proposed whereby a mutation in cycA reduces expression of the cbb(3)-type oxidase, affecting oxygen consumption rate by the cells and consequently preventing maximal expression of the periplasmic nitrate reductase during the first days of the growth period.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0378-1097
pubmed:author
pubmed:issnType
Print
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
188-94
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Role of Bradyrhizobium japonicum cytochrome c550 in nitrite and nitrate respiration.
pubmed:affiliation
Estación Experimental del Zaidín, Consejo Superior de Investigaciones Cientificas, C/Profesor Albareda 1, Granada, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't