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M94A0319.TXT
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1994-10-08
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Document 0319
DOCN M94A0319
TI Molecular dynamics simulation of a leucine zipper motif predicted for
the integrase of human immunodeficiency virus type 1.
DT 9412
AU Wang CY; Yang CF; Lai MC; Lee YH; Lee TL; Lin TH; Institute of
Biomedical Science, National Tsing Hua University,; Taiwan, Republic of
China.
SO Biopolymers. 1994 Aug;34(8):1027-36. Unique Identifier : AIDSLINE
MED/94355641
AB We have used the molecular dynamics (MD) simulation package AMBER4 to
search the conformation of a peptide predicted as a leucine zipper motif
for the human immunodeficiency virus type 1 integrase protein (HIV
IN-LZM). The peptide is composed of 22 amino acid residues and its
location is from Val 151 to Leu 172. The searching procedure also
includes two known alpha-helices that served as positive
controls--namely, a 22-residue GCN4-p1 (LZM) and a 20-residue poly
(L-alanine) (PLA). A 21-residue peptide extracted from a cytochrome C
crystal (CCC-t) with determined conformation as a beta-turn is also
included as a negative control. At the beginning of the search, two
starting conformations--namely, the standard right-handed alpha-helix
and the fully stretched conformations--are generated for each peptide.
Structures generated as standard alpha-helix are equilibrated at room
temperature for 90 ps while structures generated as a fully stretched
one are equilibrated at 600 K for 120 ps. The CCC-t and PLA helices are
nearly destroyed from the beginning of equilibration. However, for both
the HIV IN-LZM and the GCN4-p1 LZM structures, there is substantial
helicity being retained throughout the entire course of equilibration.
Although helix propagation profiles calculated indicate that both
peptides possess about the same propensity to form an alpha-helix, the
HIV IN-LZM helix appears to be more stable than the GCN4-p1 one as
judged by a variety of analyses on both structures generated during the
equilibration course. The fact that predicted HIV IN-LZM can exist as an
alpha-helix is also supported by the results of high temperature
equilibration run on the fully stretched structures generated. In this
run, the RMS deviations between the backbone atoms of the structures
with the lowest potential energy (PE) identified within every 2 ps and
the structure with the lowest PE searched in the same course of
simulation are calculated. For both the HIV IN-LZM and the GCN4-p1 LZM,
these rms values decrease with the decrease of PE, which indicates that
both structures are closer in conformations as their PEs are moved
deeper into the PE well.
DE Amino Acid Sequence *Computer Simulation DNA
Nucleotidyltransferases/*GENETICS HIV-1/*ENZYMOLOGY *Models, Molecular
Molecular Sequence Data Retroviridae Proteins/*GENETICS Support,
Non-U.S. Gov't Thermodynamics JOURNAL ARTICLE
SOURCE: National Library of Medicine. NOTICE: This material may be
protected by Copyright Law (Title 17, U.S.Code).