Linked Life Data

18599837

Source:http://linkedlifedata.com/resource/pubmed/id/18599837

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 7
pubmed:dateCreated
2008-7-7
pubmed:databankReference
pubmed:abstractText
Strains Sp7 and Cd of Azospirillum brasilense, a plant growth-promoting rhizobacterium, differ in synthesis of carotenoids. While colonies of strain Sp7 have a white-cream colour on plates, colonies of strain Cd are orange-pink coloured because of the synthesis of carotenoids. Screening of a mini-Tn5 mutant library of A. brasilense Sp7 revealed two orange-pink-coloured mutants that produced carotenoids. Cloning and sequencing of the Tn5 flanking region in both the carotenoid-producing mutants of Sp7 revealed insertion of Tn5 in an ORF encoding anti-sigma factor, a ChrR-like protein. The upstream region of the Tn5-mutated ORF contained another ORF that encoded an extra-cytoplasmic function (ECF)-class sigma factor (sigma(E), RpoE). When the nucleotide sequences of the corresponding ORFs from the carotenoid-producing strain Cd were analysed, the sequence of the Cd sigma(E) was identical to that of the carotenoid non-producing strain Sp7, but the Cd anti-sigma(E) ORF had a deletion that caused frame shifting and creation of a stop codon. This resulted in the premature termination of the protein, which was about 7 kDa smaller than the Sp7 anti-sigma(E). Cloning of Sp7 anti-sigma(E) in a broad-host-range expression vector and expression in A. brasilense Cd and in the anti-sigma(E) knockout mutant of A. brasilense Sp7 resulted in the inhibition of carotenoid synthesis. Similarly, cloning and overexpression of A. brasilense Sp7 sigma(E) in A. brasilense Sp7 resulted in the production of carotenoids. These observations clearly indicate that carotenoid synthesis in A. brasilense is controlled by sigma(E) with its cognate anti-sigma(E).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1350-0872
pubmed:author
pubmed:issnType
Print
pubmed:volume
154
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2096-105
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
An extra-cytoplasmic function sigma factor and anti-sigma factor control carotenoid biosynthesis in Azospirillum brasilense.
pubmed:affiliation
School of Biotechnology, Faculty of Science, Banaras Hindu University, Varanasi-221005, India.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't