1fgl: Difference between revisions
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|PDB= 1fgl |SIZE=350|CAPTION= <scene name='initialview01'>1fgl</scene>, resolution 1.8Å | |PDB= 1fgl |SIZE=350|CAPTION= <scene name='initialview01'>1fgl</scene>, resolution 1.8Å | ||
|SITE= | |SITE= | ||
|LIGAND= | |LIGAND= <scene name='pdbligand=BAL:BETA-ALANINE'>BAL</scene>, <scene name='pdbligand=NLE:NORLEUCINE'>NLE</scene> | ||
|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] | |ACTIVITY= <span class='plainlinks'>[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] </span> | ||
|GENE= CYCLOPHILIN ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens]) | |GENE= CYCLOPHILIN ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens]) | ||
|DOMAIN= | |||
|RELATEDENTRY= | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1fgl FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1fgl OCA], [http://www.ebi.ac.uk/pdbsum/1fgl PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1fgl RCSB]</span> | |||
}} | }} | ||
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[[Category: cyclophilin]] | [[Category: cyclophilin]] | ||
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Revision as of 20:22, 30 March 2008
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| , resolution 1.8Å | |||||||
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| Ligands: | , | ||||||
| Gene: | CYCLOPHILIN (Homo sapiens) | ||||||
| Activity: | Peptidylprolyl isomerase, with EC number 5.2.1.8 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| 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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