Linked Life Data

2664454

Source:http://linkedlifedata.com/resource/pubmed/id/2664454

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
1989-8-25
pubmed:abstractText
The first step in heme biosynthesis is the formation of 5-aminolevulinic acid (ALA). We have isolated, mapped and characterized a large number of Salmonella typhimurium mutants auxotrophic for ALA. These mutants carry defects in either one of two genes, both required for ALA synthesis. The previously identified hemA gene maps at 35 min, and the hemL gene maps at 5 min on the S. typhimurium genetic map. Mutants in hemA and hemL are defective for aerobic and anaerobic respiration, and appear to be oxygen sensitive. The Hem- phenotype of hemL mutants is less severe than that of hemA mutants. Although hemA and hemL mutants are deficient in heme synthesis, genetic tests indicate that they still synthesize two minor products of the heme pathway, siroheme and cobalamin (vitamin B12), under anaerobic conditions. In contrast, hemB, hemC and cysG mutants, blocked after ALA synthesis, make neither siroheme nor vitamin B12. Double mutants defective in both hemA and hemL also make siroheme. We suggest that hemA and hemL are required for one route of ALA synthesis and that a second, minor route of ALA synthesis may operate in S. typhimurium; this second pathway would be independent of the hemA and hemL functions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0026-8925
pubmed:author
pubmed:issnType
Print
pubmed:volume
216
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
303-14
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Heme-deficient mutants of Salmonella typhimurium: two genes required for ALA synthesis.
pubmed:affiliation
Department of Biology, University of Utah, Salt Lake City 84112.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't