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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Molecular and structural characterization of HIV-1 subtype B Brazilian isolates with GWGR tetramer at the tip of the V3-loop

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Author(s):
Leal, Elcio [1] ; Silva, Wilson P. [1] ; Sucupira, Maria C. [1] ; Janini, L. Mario [1] ; Diaz, Ricardo S. [1]
Total Authors: 5
Affiliation:
[1] Univ Fed Sao Paulo, BR-04039032 Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: VIROLOGY; v. 381, n. 2, p. 222-229, NOV 25 2008.
Web of Science Citations: 13
Abstract

One of most intriguing features of the HIV-1 subtype B epidemic in Brazil is the high frequency of isolates exhibiting tryptophan (W) in the tetramer (GWGR) at the tip of the V3 loop. We observed that the frequencies of glutamic and aspartic acids at site 25 of the V3 loop are quite distinct in GWGR isolates compared with viruses with other tetramers. The basic amino acids at sites 11 and 25 of V3 are strongly linked with CCR5-to-CXCR4 coreceptor shift. We therefore predicted phenotype usage and found that GWGR isolates are exclusively CCR5-using. Further evidence of this came from intrahost sequences, where basic amino acid substitutions at sites 11 and 25 emerged only in isolates presenting a tryptophan-to-glycine replacement at the tetramer of the V3. In addition, modeled 3D-structures of the V3 loop of GWGR and GGGR in intrahost viruses differ essentially in the binding region of the coreceptor. (C) 2008 Elsevier Inc. All rights reserved. (AU)