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| - | [[Image:2a7k.gif|left|200px]] | |
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| - | {{Structure
| + | ==carboxymethylproline synthase (CarB) from pectobacterium carotovora, apo enzyme== |
| - | |PDB= 2a7k |SIZE=350|CAPTION= <scene name='initialview01'>2a7k</scene>, resolution 2.240Å
| + | <StructureSection load='2a7k' size='340' side='right'caption='[[2a7k]], [[Resolution|resolution]] 2.24Å' scene=''> |
| - | |SITE=
| + | == Structural highlights == |
| - | |LIGAND=
| + | <table><tr><td colspan='2'>[[2a7k]] is a 9 chain structure with sequence from [https://en.wikipedia.org/wiki/Pectobacterium_carotovorum Pectobacterium carotovorum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2A7K OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2A7K FirstGlance]. <br> |
| - | |ACTIVITY=
| + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.24Å</td></tr> |
| - | |GENE= CarB ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=554 Pectobacterium carotovorum])
| + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2a7k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2a7k OCA], [https://pdbe.org/2a7k PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2a7k RCSB], [https://www.ebi.ac.uk/pdbsum/2a7k PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2a7k ProSAT]</span></td></tr> |
| - | }}
| + | </table> |
| - | | + | == Function == |
| - | '''carboxymethylproline synthase (CarB) from pectobacterium carotovora, apo enzyme''' | + | [https://www.uniprot.org/uniprot/CARB_PECCC CARB_PECCC] Catalyzes the formation of (2S,5S)-carboxymethylproline (t-CMP) from malonyl-CoA and (S)-1-pyrroline-5-carboxylate, the first step in the biosynthesis of (5R)-carbapen-2-em-3-carboxylate, a beta-lactam antibiotic of the carbapenem class (PubMed:15595850, PubMed:14625287). Also catalyzes the independent decarboxylation of malonyl-CoA and methylmalonyl-CoA and the hydrolysis of CoA esters such as acetyl-CoA and propionyl-CoA (PubMed:15595850). Catalyzes the reaction with a C2 epimeric mixture of methylmalonyl-CoA to give a 55:45 mixture of (6R)- and (6S)-epimers of 6-methyl-t-CMP, under standard incubation conditions (PubMed:21505494).<ref>PMID:14625287</ref> <ref>PMID:15595850</ref> <ref>PMID:15726176</ref> <ref>PMID:18972478</ref> <ref>PMID:21505494</ref> |
| - | | + | == Evolutionary Conservation == |
| - | | + | [[Image:Consurf_key_small.gif|200px|right]] |
| - | ==Overview== | + | Check<jmol> |
| - | The first step in the biosynthesis of the medicinally important carbapenem family of beta-lactam antibiotics is catalyzed by carboxymethylproline synthase (CarB), a unique member of the crotonase superfamily. CarB catalyzes formation of (2S,5S)-carboxymethylproline [(2S,5S)-t-CMP] from malonyl-CoA and l-glutamate semialdehyde. In addition to using a cosubstrate, CarB catalyzes C-C and C-N bond formation processes as well as an acyl-coenzyme A hydrolysis reaction. We describe the crystal structure of CarB in the presence and absence of acetyl-CoA at 2.24 A and 3.15 A resolution, respectively. The structures reveal that CarB contains a conserved oxy-anion hole probably required for decarboxylation of malonyl-CoA and stabilization of the resultant enolate. Comparison of the structures reveals that conformational changes (involving His(229)) in the cavity predicted to bind l-glutamate semialdehyde occur on (co)substrate binding. Mechanisms for the formation of the carboxymethylproline ring are discussed in the light of the structures and the accompanying studies using isotopically labeled substrates; cyclization via 1,4-addition is consistent with the observed labeling results (providing that hydrogen exchange at the C-6 position of carboxymethylproline does not occur). The side chain of Glu(131) appears to be positioned to be involved in hydrolysis of the carboxymethylproline-CoA ester intermediate. Labeling experiments ruled out the possibility that hydrolysis proceeds via an anhydride in which water attacks a carbonyl derived from Glu(131), as proposed for 3-hydroxyisobutyryl-CoA hydrolase. The structural work will aid in mutagenesis studies directed at altering the selectivity of CarB to provide intermediates for the production of clinically useful carbapenems.
| + | <jmolCheckbox> |
| - | | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/a7/2a7k_consurf.spt"</scriptWhenChecked> |
| - | ==About this Structure== | + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> |
| - | 2A7K is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Pectobacterium_carotovorum Pectobacterium carotovorum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2A7K OCA].
| + | <text>to colour the structure by Evolutionary Conservation</text> |
| - | | + | </jmolCheckbox> |
| - | ==Reference== | + | </jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2a7k ConSurf]. |
| - | Structural and mechanistic studies on carboxymethylproline synthase (CarB), a unique member of the crotonase superfamily catalyzing the first step in carbapenem biosynthesis., Sleeman MC, Sorensen JL, Batchelar ET, McDonough MA, Schofield CJ, J Biol Chem. 2005 Oct 14;280(41):34956-65. Epub 2005 Aug 11. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16096274 16096274]
| + | <div style="clear:both"></div> |
| | + | == References == |
| | + | <references/> |
| | + | __TOC__ |
| | + | </StructureSection> |
| | + | [[Category: Large Structures]] |
| | [[Category: Pectobacterium carotovorum]] | | [[Category: Pectobacterium carotovorum]] |
| - | [[Category: Single protein]]
| + | [[Category: Batchelar ET]] |
| - | [[Category: Batchelar, E T.]] | + | [[Category: McDonough MA]] |
| - | [[Category: McDonough, M A.]] | + | [[Category: Schofield CJ]] |
| - | [[Category: Schofield, C J.]] | + | [[Category: Sleeman MC]] |
| - | [[Category: Sleeman, M C.]] | + | [[Category: Sorensen JL]] |
| - | [[Category: Sorensen, J L.]] | + | |
| - | [[Category: antibiotic]]
| + | |
| - | [[Category: beta-lactam]]
| + | |
| - | [[Category: carbapenam]]
| + | |
| - | [[Category: carbapenem]]
| + | |
| - | [[Category: crotonase]]
| + | |
| - | | + | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 15:46:18 2008''
| + | |
| Structural highlights
Function
CARB_PECCC Catalyzes the formation of (2S,5S)-carboxymethylproline (t-CMP) from malonyl-CoA and (S)-1-pyrroline-5-carboxylate, the first step in the biosynthesis of (5R)-carbapen-2-em-3-carboxylate, a beta-lactam antibiotic of the carbapenem class (PubMed:15595850, PubMed:14625287). Also catalyzes the independent decarboxylation of malonyl-CoA and methylmalonyl-CoA and the hydrolysis of CoA esters such as acetyl-CoA and propionyl-CoA (PubMed:15595850). Catalyzes the reaction with a C2 epimeric mixture of methylmalonyl-CoA to give a 55:45 mixture of (6R)- and (6S)-epimers of 6-methyl-t-CMP, under standard incubation conditions (PubMed:21505494).[1] [2] [3] [4] [5]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
References
- ↑ Sleeman MC, Schofield CJ. Carboxymethylproline synthase (CarB), an unusual carbon-carbon bond-forming enzyme of the crotonase superfamily involved in carbapenem biosynthesis. J Biol Chem. 2004 Feb 20;279(8):6730-6. Epub 2003 Nov 18. PMID:14625287 doi:http://dx.doi.org/10.1074/jbc.M311824200
- ↑ Gerratana B, Arnett SO, Stapon A, Townsend CA. Carboxymethylproline synthase from Pectobacterium carotorova: a multifaceted member of the crotonase superfamily. Biochemistry. 2004 Dec 21;43(50):15936-45. PMID:15595850 doi:http://dx.doi.org/10.1021/bi0483662
- ↑ Sorensen JL, Sleeman MC, Schofield CJ. Synthesis of deuterium labelled L- and D-glutamate semialdehydes and their evaluation as substrates for carboxymethylproline synthase (CarB)--implications for carbapenem biosynthesis. Chem Commun (Camb). 2005 Mar 7;(9):1155-7. Epub 2005 Jan 13. PMID:15726176 doi:http://dx.doi.org/10.1039/b416423g
- ↑ Batchelar ET, Hamed RB, Ducho C, Claridge TD, Edelmann MJ, Kessler B, Schofield CJ. Thioester hydrolysis and C-C bond formation by carboxymethylproline synthase from the crotonase superfamily. Angew Chem Int Ed Engl. 2008;47(48):9322-5. doi: 10.1002/anie.200803906. PMID:18972478 doi:http://dx.doi.org/10.1002/anie.200803906
- ↑ Hamed RB, Gomez-Castellanos JR, Thalhammer A, Harding D, Ducho C, Claridge TD, Schofield CJ. Stereoselective C-C bond formation catalysed by engineered carboxymethylproline synthases. Nat Chem. 2011 May;3(5):365-71. doi: 10.1038/nchem.1011. Epub 2011 Apr 3. PMID:21505494 doi:http://dx.doi.org/10.1038/nchem.1011
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