From Proteopedia
(Difference between revisions)
proteopedia linkproteopedia link
|
|
Line 1: |
Line 1: |
- | [[Image:1ghd.gif|left|200px]] | + | {{Seed}} |
| + | [[Image:1ghd.png|left|200px]] |
| | | |
| <!-- | | <!-- |
Line 9: |
Line 10: |
| {{STRUCTURE_1ghd| PDB=1ghd | SCENE= }} | | {{STRUCTURE_1ghd| PDB=1ghd | SCENE= }} |
| | | |
- | '''Crystal structure of the glutaryl-7-aminocephalosporanic acid acylase by mad phasing'''
| + | ===Crystal structure of the glutaryl-7-aminocephalosporanic acid acylase by mad phasing=== |
| | | |
| | | |
- | ==Overview==
| + | <!-- |
- | Glutaryl 7-aminocephalosporanic acid acylase of Pseudomonas sp. 130 (C130) was irreversibly inhibited in a time-dependent manner by two substrate analogs bearing side chains of variable length, namely 7beta-bromoacetyl aminocephalosporanic acid (BA-7-ACA) and 7beta-3-bromopropionyl aminocephalosporanic acid (BP-7-ACA). The inhibition of the enzyme with BA-7-ACA was attributable to reaction with a single amino acid residue within the beta-subunit proven by comparative matrix assisted laser desorption/ionization-time of flight mass spectrometry. Further mass spectrometric analysis demonstrated that the fourth tryptophan residue of the beta-subunit, Trp-B4, was alkylated by BA-7-ACA. By (1)H-(13)C HSQC spectroscopy of C130 labeled by BA-2-(13)C-7-ACA, it was shown that tryptophan residue(s) in the enzyme was alkylated, forming a carbon-carbon bond. Replacing Trp-B4 with other amino acid residues caused increases in K(m), decreases in k(cat), and instability of enzyme activity. None of the mutant enzymes except W-B4Y could be affinity-alkylated, but all were competitively inhibited by BA-7-ACA. Kinetic studies revealed that both BA-7-ACA and BP-7-ACA could specifically alkylate Trp-B4 of C130 as well as Tyr-B4 of the mutant W-B4Y. Because these alkylations were energy-requiring under physiological conditions, it is likely that the affinity labeling reactions were catalyzed by the C130 enzyme itself. The Trp-B4 residue is located in the middle of a characteristic alphabetabetaalpha sandwich structure. Therefore, a large conformational alteration during inhibitor binding and transition state formation is likely and suggests that a major conformational change is induced by substrate binding during the course of catalysis.
| + | The line below this paragraph, {{ABSTRACT_PUBMED_11782466}}, adds the Publication Abstract to the page |
| + | (as it appears on PubMed at http://www.pubmed.gov), where 11782466 is the PubMed ID number. |
| + | --> |
| + | {{ABSTRACT_PUBMED_11782466}} |
| | | |
| ==About this Structure== | | ==About this Structure== |
Line 35: |
Line 39: |
| [[Category: Zhao, G.]] | | [[Category: Zhao, G.]] |
| [[Category: Cephalosporin acylase]] | | [[Category: Cephalosporin acylase]] |
- | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 17:33:46 2008'' | + | |
| + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 1 05:17:16 2008'' |
Revision as of 02:17, 1 July 2008
Template:STRUCTURE 1ghd
Crystal structure of the glutaryl-7-aminocephalosporanic acid acylase by mad phasing
Template:ABSTRACT PUBMED 11782466
About this Structure
1GHD is a Protein complex structure of sequences from Pseudomonas sp. 130. Full crystallographic information is available from OCA.
Reference
Affinity alkylation of the Trp-B4 residue of the beta -subunit of the glutaryl 7-aminocephalosporanic acid acylase of Pseudomonas sp. 130., Huang X, Zeng R, Ding X, Mao X, Ding Y, Rao Z, Xie Y, Jiang W, Zhao G, J Biol Chem. 2002 Mar 22;277(12):10256-64. Epub 2002 Jan 8. PMID:11782466
Page seeded by OCA on Tue Jul 1 05:17:16 2008
Categories: Protein complex | Pseudomonas sp. 130 | Bartlam, M. | Ding, Y. | He, H. | Jiang, F. | Jiang, W. | Liu, Y. | Mao, X. | Rao, Z. | Tang, H. | Ye, S. | Zhang, S. | Zhao, G. | Cephalosporin acylase