Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
1991-9-4
pubmed:databankReference
pubmed:abstractText
Mammalian tissues contain protein carboxyl methyltransferases that catalyze the transfer of methyl groups from S-adenosylmethionine to the free carboxyl groups of D-aspartyl or L-isoaspartyl residues (EC 2.1.1.77). These enzymes have been postulated to play a role in the repair and/or degradation of spontaneously damaged proteins. We have now characterized a similar activity from Escherichia coli that recognizes L-isoaspartyl-containing peptides as well as protein substrates such as ovalbumin. The enzyme was purified by DEAE-cellulose, hydroxylapatite, Sephadex G-100, polyaspartate, and reversed-phase chromatography and was shown to consist of a single 24-kDa polypeptide chain. The sequence determined for the N-terminal 39 residues was used to design an oligonucleotide probe that allowed the precise localization of its structural gene (pcm) on the physical map of the E. coli chromosome at 59 min. Transformation of E. coli cells with a plasmid containing DNA from this region results in a 3-4-fold overproduction of enzyme activity. The nucleotide sequence determined for the pcm gene and its flanking regions was used to deduce a mature amino acid sequence of 207 residues with a calculated molecular weight of 23,128. This sequence shows 30.8% sequence identity with the human L-isoaspartyl/D-aspartyl methyltransferase and suggests that this enzyme catalyzes a fundamental reaction in both procaryotic and eucaryotic cells.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
266
pubmed:geneSymbol
pcm
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14562-72
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Purification, gene cloning, and sequence analysis of an L-isoaspartyl protein carboxyl methyltransferase from Escherichia coli.
pubmed:affiliation
Department of Chemistry and Biochemistry, University of California, Los Angeles 90024-1569.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.