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1tzm
From Proteopedia
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|PDB= 1tzm |SIZE=350|CAPTION= <scene name='initialview01'>1tzm</scene>, resolution 2.08Å | |PDB= 1tzm |SIZE=350|CAPTION= <scene name='initialview01'>1tzm</scene>, resolution 2.08Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand= | + | |LIGAND= <scene name='pdbligand=C2N:B-CHLORO-D-ALANINE'>C2N</scene>, <scene name='pdbligand=NAK:AMINO-ACRYLATE'>NAK</scene>, <scene name='pdbligand=PLP:PYRIDOXAL-5'-PHOSPHATE'>PLP</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> |
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/1-aminocyclopropane-1-carboxylate_deaminase 1-aminocyclopropane-1-carboxylate deaminase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.99.7 3.5.99.7] | + | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/1-aminocyclopropane-1-carboxylate_deaminase 1-aminocyclopropane-1-carboxylate deaminase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.99.7 3.5.99.7] </span> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1tyz|1TYZ]], [[1tz2|1TZ2]], [[1rqx|1RQX]], [[1tzj|1TZJ]], [[1tzk|1TZK]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1tzm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tzm OCA], [http://www.ebi.ac.uk/pdbsum/1tzm PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1tzm RCSB]</span> | ||
}} | }} | ||
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[[Category: Zhao, Z.]] | [[Category: Zhao, Z.]] | ||
[[Category: Zhou, Q.]] | [[Category: Zhou, Q.]] | ||
| - | [[Category: C2N]] | ||
| - | [[Category: NAK]] | ||
| - | [[Category: PLP]] | ||
| - | [[Category: SO4]] | ||
[[Category: accd]] | [[Category: accd]] | ||
[[Category: complex]] | [[Category: complex]] | ||
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[[Category: substrate]] | [[Category: substrate]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 00:03:19 2008'' |
Revision as of 21:03, 30 March 2008
| |||||||
| , resolution 2.08Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , | ||||||
| Activity: | 1-aminocyclopropane-1-carboxylate deaminase, with EC number 3.5.99.7 | ||||||
| Related: | 1TYZ, 1TZ2, 1RQX, 1TZJ, 1TZK
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of ACC deaminase complexed with substrate analog b-chloro-D-alanine
Overview
1-Aminocyclopropane-1-carboxylate (ACC) deaminase is a pyridoxal 5'-phosphate (PLP) dependent enzyme catalyzing the opening of the cyclopropane ring of ACC to give alpha-ketobutyric acid and ammonia as the products. This ring cleavage reaction is unusual because the substrate, ACC, contains no abstractable alpha-proton and the carboxyl group is retained in the product. How the reaction is initiated to generate an alpha-carbanionic intermediate, which is the common entry for most PLP-dependent reactions, is not obvious. To gain insight into this unusual ring-opening reaction, we have solved the crystal structures of ACC deaminase from Pseudomonas sp. ACP in complex with substrate ACC, an inhibitor, 1-aminocyclopropane-1-phosphonate (ACP), the product alpha-ketobutyrate, and two d-amino acids. Several notable observations of these structural studies include the following: (1) a typically elusive gem-diamine intermediate is trapped in the enzyme complex with ACC or ACP; (2) Tyr294 is in close proximity (3.0 A) to the pro-S methylene carbon of ACC in the gem-diamine complexes, implicating a direct role of this residue in the ring-opening reaction; (3) Tyr294 may also be responsible for the abstraction of the alpha-proton from d-amino acids, a prelude to the subsequent deamination reaction; (4) the steric hindrance precludes accessibility of active site functional groups to the l-amino acid substrates and may account for the stereospecificity of this enzyme toward d-amino acids. These structural data provide evidence favoring a mechanism in which the ring cleavage is induced by a nucleophilic attack at the pro-S beta-methylene carbon of ACC, with Tyr294 as the nucleophile. However, these observations are also consistent with an alternative mechanistic possibility in which the ring opening is acid-catalyzed and may be facilitated by charge relay through PLP, where Tyr294 functions as a general acid. The results of mutagenesis studies corroborated the assigned critical role for Tyr294 in the catalysis.
About this Structure
1TZM is a Single protein structure of sequence from Pseudomonas sp.. Full crystallographic information is available from OCA.
Reference
Structural analysis of Pseudomonas 1-aminocyclopropane-1-carboxylate deaminase complexes: insight into the mechanism of a unique pyridoxal-5'-phosphate dependent cyclopropane ring-opening reaction., Karthikeyan S, Zhou Q, Zhao Z, Kao CL, Tao Z, Robinson H, Liu HW, Zhang H, Biochemistry. 2004 Oct 26;43(42):13328-39. PMID:15491139
Page seeded by OCA on Mon Mar 31 00:03:19 2008
Categories: 1-aminocyclopropane-1-carboxylate deaminase | Pseudomonas sp. | Single protein | Kao, C L. | Karthikeyan, S. | Liu, H W. | Robinson, H. | Tao, Z. | Zhang, H. | Zhao, Z. | Zhou, Q. | Accd | Complex | Crystal | Plp | Structure | Substrate
