1fgl: Difference between revisions
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[[Image:1fgl.gif|left|200px]] | [[Image:1fgl.gif|left|200px]] | ||
'''CYCLOPHILIN A COMPLEXED WITH A FRAGMENT OF HIV-1 GAG PROTEIN''' | {{Structure | ||
|PDB= 1fgl |SIZE=350|CAPTION= <scene name='initialview01'>1fgl</scene>, resolution 1.8Å | |||
|SITE= | |||
|LIGAND= | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Peptidylprolyl_isomerase Peptidylprolyl isomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.2.1.8 5.2.1.8] | |||
|GENE= CYCLOPHILIN ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens]) | |||
}} | |||
'''CYCLOPHILIN A COMPLEXED WITH A FRAGMENT OF HIV-1 GAG PROTEIN''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1FGL is a [ | 1FGL is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FGL OCA]. | ||
==Reference== | ==Reference== | ||
Cyclophilin A complexed with a fragment of HIV-1 gag protein: insights into HIV-1 infectious activity., Zhao Y, Chen Y, Schutkowski M, Fischer G, Ke H, Structure. 1997 Jan 15;5(1):139-46. PMID:[http:// | Cyclophilin A complexed with a fragment of HIV-1 gag protein: insights into HIV-1 infectious activity., Zhao Y, Chen Y, Schutkowski M, Fischer G, Ke H, Structure. 1997 Jan 15;5(1):139-46. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/9016720 9016720] | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Peptidylprolyl isomerase]] | [[Category: Peptidylprolyl isomerase]] | ||
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[[Category: Schutkowski, M.]] | [[Category: Schutkowski, M.]] | ||
[[Category: Zhao, Y.]] | [[Category: Zhao, Y.]] | ||
[[Category: | [[Category: aid]] | ||
[[Category: binding protein for cyclosporin | [[Category: binding protein for cyclosporin some]] | ||
[[Category: complex (isomerase/peptide)]] | [[Category: complex (isomerase/peptide)]] | ||
[[Category: cyclophilin]] | [[Category: cyclophilin]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:08:50 2008'' | ||
Revision as of 12:08, 20 March 2008
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| , resolution 1.8Å | |||||||
|---|---|---|---|---|---|---|---|
| Gene: | CYCLOPHILIN (Homo sapiens) | ||||||
| Activity: | Peptidylprolyl isomerase, with EC number 5.2.1.8 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CYCLOPHILIN A COMPLEXED WITH A FRAGMENT OF HIV-1 GAG PROTEIN
OverviewOverview
BACKGROUND: Cyclophilin A (CyPA), a receptor of the immunosuppressive drug cyclosporin A, catalyzes the cis-trans isomerization of peptidyl-prolyl bonds and is required for the infectious activity of human immunodeficiency virus type 1 (HIV-1). The crystal structure of CyPA complexed with a fragment of the HIV-1 gag protein should provide insights into the nature of CyPA-gag interactions and may suggest a role for CyPA in HIV-1 infectious activity. RESULTS: The crystal structure of CyPA complexed with a 25 amino acid peptide of HIV-1 gag capsid protein (25-mer) was determined and refined to an R factor of 0.195 at 1.8 A resolution. The sequence Ala88-Gly89-Pro90-Ile91 of the gag fragment is the major portion to bind to the active site of CyPA. Two residues of the 25-mer (Pro90-Ile91) bind to CyPA in a similar manner to two residues (Pro-Phe) of the CyPA substrate, succinyl-Ala-Ala-Pro-Phe-p-nitroanilide (AAPF). However, the N-terminus of the 25-mer (Ala88-Gly89) exhibits a different hydrogen-bonding pattern and molecular conformation than AAPF. The peptidyl-prolyl bond between Gly89 and Pro90 of the 25-mer has a trans conformation, in contrast to the cis conformation observed in other known CyPA-peptide complexes. The residue preceding proline, Gly89, has an unfavorable backbone conformation usually only adopted by glycine. CONCLUSIONS: The unfavorable backbone conformation of Gly89 of the gag 25-mer fragment suggests that binding between HIV-1 gag protein and CyPA requires a special sequence, Gly-Pro. Thus, in HIV-1 infectivity, CyPA is likely to function as a chaperone, rather than as a cis-trans isomerase. However, the observation of similarities between the C termini of the 25-mer and the substrate AAPF means that the involvement of the cis-trans isomerase activity of CyPA cannot be completely ruled out.
About this StructureAbout this Structure
1FGL is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Cyclophilin A complexed with a fragment of HIV-1 gag protein: insights into HIV-1 infectious activity., Zhao Y, Chen Y, Schutkowski M, Fischer G, Ke H, Structure. 1997 Jan 15;5(1):139-46. PMID:9016720
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