Linked Life Data

2506452

Source:http://linkedlifedata.com/resource/pubmed/id/2506452

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6239
pubmed:dateCreated
1989-10-13
pubmed:abstractText
Sulphur is unique among the main elements of living cells in that it is covalently bound to biopolymers but does not occur in the biopolymer backbone. Indeed, most of the bacterial sulphur content resides in the methionine and cysteine side-chains of proteins. The growth yield of an organism under conditions of sulphur limitation could therefore be greatly enhanced by mutations that substitute Met and Cys in the organism's proteins for sulphur-free amino acids. Because the saving in sulphur would increase with such accumulating mutations, Met and Cys changes could be progressively selected. Abundant proteins should be the prime targets of such a selection. A few published observations give credence to this scenario. Sulphate permease, which is abundantly produced by sulphur-starved Salmonella typhimurium, lacks Met and Cys residues. Also, two species of marine purple bacteria synthesize more protein than can be expected from a limited sulphate supply. We now report that the cyanobacterium Calothrix sp. PCC 7601 (referred to here as Calothrix) encodes sulphur-depleted versions of its most abundant proteins--phycocyanin and its auxiliary polypeptides--which it specifically expresses under conditions of sulphur limitation. Although these proteins do not take part in the fixation of sulphur, their elevated synthesis affects the sulphur budget of cyanobacterial cells. Direct evidence is thus provided that the structure of macromolecules can be subject to metabolic optimization.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0028-0836
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
341
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
245-8
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Adaptive eradication of methionine and cysteine from cyanobacterial light-harvesting proteins.
pubmed:affiliation
Département de Biochimie et Génétique Moléculaire, Institut Pasteur, Paris, France.
pubmed:publicationType
Journal Article, Comparative Study