1ssa: Difference between revisions
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|PDB= 1ssa |SIZE=350|CAPTION= <scene name='initialview01'>1ssa</scene>, resolution 2.0Å | |PDB= 1ssa |SIZE=350|CAPTION= <scene name='initialview01'>1ssa</scene>, resolution 2.0Å | ||
|SITE= | |SITE= | ||
|LIGAND= <scene name='pdbligand=SO4:SULFATE ION'>SO4</scene> | |LIGAND= <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> | ||
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
|DOMAIN= | |||
|RELATEDENTRY= | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ssa FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ssa OCA], [http://www.ebi.ac.uk/pdbsum/1ssa PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1ssa RCSB]</span> | |||
}} | }} | ||
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[[Category: Martin, P D.]] | [[Category: Martin, P D.]] | ||
[[Category: Ram, M L.]] | [[Category: Ram, M L.]] | ||
[[Category: hydrolase(endoribonuclease)]] | [[Category: hydrolase(endoribonuclease)]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:46:16 2008'' | ||
Revision as of 23:46, 30 March 2008
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
A STRUCTURAL INVESTIGATION OF CATALYTICALLY MODIFIED F12OL AND F12OY SEMISYNTHETIC RIBONUCLEASES
OverviewOverview
The structures of two catalytically modified semisynthetic RNases obtained by replacing phenylalanine 120 with leucine and tyrosine have been determined and refined at a resolution of 2.0 A (R = 0.161 and 0.184, respectively). These structures have been compared with the refined 1.8-A structure (R = 0.204) of the fully active phenylalanine-containing enzyme (Martin PD, Doscher MS, Edwards BFP, 1987, J Biol Chem 262:15930-15938) and with the catalytically defective D121A (2.0 A, R = 0.172) and D121N (2.0 A, R = 0.186) analogs (deMel VSJ, Martin PD, Doscher MS, Edwards BFP, 1992, J Biol Chem 267:247-256). The movement away from the active site of the loop containing residues 65-72 is seen in all three catalytically defective analogs--F120L, D121A, and D121N--but not in the fully active (or hyperactive) F120Y. The insertion of the phenolic hydroxyl of Tyr 120 into a hydrogen-bonding network involving the hydroxyl group of Ser 123 and a water molecule in F120Y is the likely basis for the hyperactivity toward uridine 2',3'-cyclic phosphate previously found for this analog (Hodges RS, Merrifield RB, 1974, Int J Pept Protein Res 6:397-405) as well as the threefold increase in KM for cytidine 2',3'-cyclic phosphate found for this analog by ourselves.
About this StructureAbout this Structure
1SSA is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
ReferenceReference
Structural investigation of catalytically modified F120L and F120Y semisynthetic ribonucleases., deMel VS, Doscher MS, Glinn MA, Martin PD, Ram ML, Edwards BF, Protein Sci. 1994 Jan;3(1):39-50. PMID:8142897
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