Linked Life Data

7539431

Source:http://linkedlifedata.com/resource/pubmed/id/7539431

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
1995-7-5
pubmed:abstractText
Active, recombinant p68 reverse transcriptase (RT) from human immunodeficiency virus type 2 (HIV-2), with an NH2-terminal extension containing a hexahistidine sequence was isolated from extracts of Escherichia coli by immobilized metal affinity chromatography. Treatment of the purified p68/p68 homodimer of HIV-2 RT with recombinant HIV-2 protease generates stable, active heterodimer (p68/p58) that is resistant to further hydrolysis. Analysis of this p68/p58 HIV-2 RT heterodimer revealed that while one subunit is intact p68, the p58 subunit is COOH-terminally truncated by cleavage, not at Phe440 as is seen in processing of the p66/p66 HIV-1 RT homodimer by HIV-1 protease, but at Met484. The expected COOH-terminal p10 fragment resulting from hydrolysis of p68 at Met484 is not released intact, but undergoes further cleavage at Asn494, Met503, and Tyr532. Processing of p68/p68 HIV-2 RT with the HIV-1 protease led to cleavage of the Phe440-Tyr441 bond, exactly as is seen with p66/p66 HIV-1 RT, to give the analogous p53 subunit. Studies of a peptide substrate modeled after residues 437-444 in HIV-2 RT showed that while the HIV-1 protease was able to cleave the Phe440 bond, this bond was resistant to cleavage by the HIV-2 enzyme. Our findings provide a rationale for the previous observation that the RT heterodimer isolated from HIV-2 lysates is larger than that from HIV-1. We conclude that the p68/p58 HIV-2 RT heterodimer, containing the Met484 truncated p58 subunit, is a biologically relevant form of the enzyme in vivo.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
N
pubmed:pagination
13573-9
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
The differential processing of homodimers of reverse transcriptases from human immunodeficiency viruses type 1 and 2 is a consequence of the distinct specificities of the viral proteases.
pubmed:affiliation
Upjohn Laboratories, Kalamazoo, Michigan 49001, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.