Linked Life Data

10486976

Source:http://linkedlifedata.com/resource/pubmed/id/10486976

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1999-10-18
pubmed:databankReference
pubmed:abstractText
The high-molecular-weight extracellular hemoglobin of Daphnia pulex is composed of at least three different didomain globin chains. The primary structure of one of these chains was determined at the protein and cDNA levels. Each globin domain of the polypeptide chain displays the standard structural characteristics. The first domain is preceded by a 30-residue extension containing an 18-residue unprecedented threonine-rich segment and a 12-residue preA segment which is homologous to the preA segments of other nonvertebrate globin chains. Both domains are linked together by a preA' segment, which is homologous to other preA segments and lacks the threonine-rich segment. Dimerization of the globin chains by the formation of a disulphide bridge linking the unique cysteines near the amino-termini results in a covalent, vertebrate-like tetradomain structure. The flexible amino-terminal extension most likely facilitates dimerization. The gene coding for this globin chain is interrupted by six small introns. Each domain displays two intradomain introns at the conserved positions B12.2 and G7.0. A precoding intron occurs at position preA(-27.0) and a bridge intron at occurs preA'(-13.2). We propose a crossover event as the most likely mechanism for duplication. Arthropod globin trees reflect the added effects of gene diversification, gene duplication, and species evolution. The position of monodomain intracellular globins in the tree suggests that they resemble the ancestral globin more than the derived didomain extracellular globins do.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0737-4038
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1208-18
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Daphnia pulex didomain hemoglobin: structure and evolution of polymeric hemoglobins and their coding genes.
pubmed:affiliation
Department of Biochemistry, University of Antwerp, Belgium.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't