1j5o: Difference between revisions

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CRYSTAL STRUCTURE OF MET184ILE MUTANT OF HIV-1 REVERSE TRANSCRIPTASE IN COMPLEX WITH DOUBLE STRANDED DNA TEMPLATE-PRIMER

OverviewOverview

An important component of triple-drug anti-AIDS therapy is 2', 3'-dideoxy-3'-thiacytidine (3TC, lamivudine). Single mutations at residue 184 of the reverse transcriptase (RT) in HIV cause high-level resistance to 3TC and contribute to the failure of anti-AIDS combination therapy. We have determined crystal structures of the 3TC-resistant mutant HIV-1 RT (M184I) in both the presence and absence of a DNA/DNA template-primer. In the absence of a DNA substrate, the wild-type and mutant structures are very similar. However, comparison of crystal structures of M184I mutant and wild-type HIV-1 RT with and without DNA reveals repositioning of the template-primer in the M184I/DNA binary complex and other smaller changes in residues in the dNTP-binding site. On the basis of these structural results, we developed a model that explains the ability of the 3TC-resistant mutant M184I to incorporate dNTPs but not the nucleotide analog 3TCTP. In this model, steric hindrance is expected for NRTIs with beta- or L- ring configurations, as with the enantiomer of 3TC that is used in therapy. Steric conflict between the oxathiolane ring of 3TCTP and the side chain of beta-branched amino acids (Val, Ile, Thr) at position 184 perturbs inhibitor binding, leading to a reduction in incorporation of the analog. The model can also explain the 3TC resistance of analogous hepatitis B polymerase mutants. Repositioning of the template-primer as observed in the binary complex (M184I/DNA) may also occur in the catalytic ternary complex (M184I/DNA/3TCTP) and contribute to 3TC resistance by interfering with the formation of a catalytically competent closed complex.

About this StructureAbout this Structure

1J5O is a Protein complex structure of sequences from Human immunodeficiency virus 1 and Mus musculus. This structure supersedes the now removed PDB entry 1C9R. Active as RNA-directed DNA polymerase, with EC number 2.7.7.49 Full crystallographic information is available from OCA.

ReferenceReference

Lamivudine (3TC) resistance in HIV-1 reverse transcriptase involves steric hindrance with beta-branched amino acids., Sarafianos SG, Das K, Clark AD Jr, Ding J, Boyer PL, Hughes SH, Arnold E, Proc Natl Acad Sci U S A. 1999 Aug 31;96(18):10027-32. PMID:10468556

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-[[Image:1j5o.gif|left|200px]]<br />
+[[Image:1j5o.gif|left|200px]]<br /><applet load="1j5o" size="350" color="white" frame="true" align="right" spinBox="true"
-<applet load="1j5o" size="450" color="white" frame="true" align="right" spinBox="true"
 caption="1j5o, resolution 3.5&Aring;" />
 '''CRYSTAL STRUCTURE OF MET184ILE MUTANT OF HIV-1 REVERSE TRANSCRIPTASE IN COMPLEX WITH DOUBLE STRANDED DNA TEMPLATE-PRIMER'''<br />
 ==Overview==
-An important component of triple-drug anti-AIDS therapy is 2', 3'-dideoxy-3'-thiacytidine (3TC, lamivudine). Single mutations at residue, 184 of the reverse transcriptase (RT) in HIV cause high-level resistance, to 3TC and contribute to the failure of anti-AIDS combination therapy. We, have determined crystal structures of the 3TC-resistant mutant HIV-1 RT, (M184I) in both the presence and absence of a DNA/DNA template-primer. In, the absence of a DNA substrate, the wild-type and mutant structures are, very similar. However, comparison of crystal structures of M184I mutant, and wild-type HIV-1 RT with and without DNA reveals repositioning of the, template-primer in the M184I/DNA binary complex and other smaller changes, in residues in the dNTP-binding site. On the basis of these structural, results, we developed a model that explains the ability of the, 3TC-resistant mutant M184I to incorporate dNTPs but not the nucleotide, analog 3TCTP. In this model, steric hindrance is expected for NRTIs with, beta- or L- ring configurations, as with the enantiomer of 3TC that is, used in therapy. Steric conflict between the oxathiolane ring of 3TCTP and, the side chain of beta-branched amino acids (Val, Ile, Thr) at position, 184 perturbs inhibitor binding, leading to a reduction in incorporation of, the analog. The model can also explain the 3TC resistance of analogous, hepatitis B polymerase mutants. Repositioning of the template-primer as, observed in the binary complex (M184I/DNA) may also occur in the catalytic, ternary complex (M184I/DNA/3TCTP) and contribute to 3TC resistance by, interfering with the formation of a catalytically competent closed, complex.
+An important component of triple-drug anti-AIDS therapy is 2', 3'-dideoxy-3'-thiacytidine (3TC, lamivudine). Single mutations at residue 184 of the reverse transcriptase (RT) in HIV cause high-level resistance to 3TC and contribute to the failure of anti-AIDS combination therapy. We have determined crystal structures of the 3TC-resistant mutant HIV-1 RT (M184I) in both the presence and absence of a DNA/DNA template-primer. In the absence of a DNA substrate, the wild-type and mutant structures are very similar. However, comparison of crystal structures of M184I mutant and wild-type HIV-1 RT with and without DNA reveals repositioning of the template-primer in the M184I/DNA binary complex and other smaller changes in residues in the dNTP-binding site. On the basis of these structural results, we developed a model that explains the ability of the 3TC-resistant mutant M184I to incorporate dNTPs but not the nucleotide analog 3TCTP. In this model, steric hindrance is expected for NRTIs with beta- or L- ring configurations, as with the enantiomer of 3TC that is used in therapy. Steric conflict between the oxathiolane ring of 3TCTP and the side chain of beta-branched amino acids (Val, Ile, Thr) at position 184 perturbs inhibitor binding, leading to a reduction in incorporation of the analog. The model can also explain the 3TC resistance of analogous hepatitis B polymerase mutants. Repositioning of the template-primer as observed in the binary complex (M184I/DNA) may also occur in the catalytic ternary complex (M184I/DNA/3TCTP) and contribute to 3TC resistance by interfering with the formation of a catalytically competent closed complex.
 ==About this Structure==
-J5O is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Human_immunodeficiency_virus_1 Human immunodeficiency virus 1] and [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. This structure superseeds the now removed PDB entry 1C9R. Active as [http://en.wikipedia.org/wiki/RNA-directed_DNA_polymerase RNA-directed DNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.49 2.7.7.49] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1J5O OCA].
+J5O is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Human_immunodeficiency_virus_1 Human immunodeficiency virus 1] and [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. This structure supersedes the now removed PDB entry 1C9R. Active as [http://en.wikipedia.org/wiki/RNA-directed_DNA_polymerase RNA-directed DNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.49 2.7.7.49] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1J5O OCA].
 ==Reference==
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 [[Category: Arnold, E.]]
 [[Category: Das, K.]]
-[[Category: Sarafianos, S.G.]]
+[[Category: Sarafianos, S G.]]
 [[Category: 3tc]]
 [[Category: drug resistance]]
@@ Line 27: / Line 26: @@
 [[Category: reverse transcriptase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Thu Nov  8 14:11:25 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:19:13 2008''