2trs
From Proteopedia
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| - | [[Image:2trs.jpg|left|200px]]<br /><applet load="2trs" size=" | + | [[Image:2trs.jpg|left|200px]]<br /><applet load="2trs" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2trs, resolution 2.04Å" /> | caption="2trs, resolution 2.04Å" /> | ||
'''CRYSTAL STRUCTURES OF MUTANT (BETAK87T) TRYPTOPHAN SYNTHASE ALPHA2 BETA2 COMPLEX WITH LIGANDS BOUND TO THE ACTIVE SITES OF THE ALPHA AND BETA SUBUNITS REVEAL LIGAND-INDUCED CONFORMATIONAL CHANGES'''<br /> | '''CRYSTAL STRUCTURES OF MUTANT (BETAK87T) TRYPTOPHAN SYNTHASE ALPHA2 BETA2 COMPLEX WITH LIGANDS BOUND TO THE ACTIVE SITES OF THE ALPHA AND BETA SUBUNITS REVEAL LIGAND-INDUCED CONFORMATIONAL CHANGES'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
| - | 2TRS is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Salmonella_typhimurium Salmonella typhimurium] with NA, IPL and PLS as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Tryptophan_synthase Tryptophan synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.20 4.2.1.20] Known structural/functional Sites: <scene name='pdbsite=S1:Substrate Analog Bound To The Alpha Active Site'>S1</scene> and <scene name='pdbsite=S2:Reaction Intermediate Bound To The Beta Active Site'>S2</scene>. Full crystallographic information is available from [http:// | + | 2TRS is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Salmonella_typhimurium Salmonella typhimurium] with <scene name='pdbligand=NA:'>NA</scene>, <scene name='pdbligand=IPL:'>IPL</scene> and <scene name='pdbligand=PLS:'>PLS</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Tryptophan_synthase Tryptophan synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.20 4.2.1.20] Known structural/functional Sites: <scene name='pdbsite=S1:Substrate+Analog+Bound+To+The+Alpha+Active+Site'>S1</scene> and <scene name='pdbsite=S2:Reaction+Intermediate+Bound+To+The+Beta+Active+Site'>S2</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2TRS OCA]. |
==Reference== | ==Reference== | ||
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[[Category: tryptophan biosynthesis]] | [[Category: tryptophan biosynthesis]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 10:46:56 2008'' |
Revision as of 08:46, 3 February 2008
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CRYSTAL STRUCTURES OF MUTANT (BETAK87T) TRYPTOPHAN SYNTHASE ALPHA2 BETA2 COMPLEX WITH LIGANDS BOUND TO THE ACTIVE SITES OF THE ALPHA AND BETA SUBUNITS REVEAL LIGAND-INDUCED CONFORMATIONAL CHANGES
Overview
Three-dimensional structures are reported for a mutant (betaK87T), tryptophan synthase alpha2beta2 complex with either the substrate L-serine, (betaK87T-Ser) or product L-tryptophan (betaK87T-Trp) at the active site, of the beta-subunit, in which both amino acids form external aldimines, with the coenzyme, pyridoxal phosphate. We also present structures with, L-serine bound to the beta site and either alpha-glycerol 3-phosphate, (betaK87T-Ser-GP) or indole-3-propanol phosphate (betaK87T-Ser-IPP) bound, to the active site of the alpha-subunit. The results further identify the, substrate and product binding sites in each subunit and provide insight, into conformational changes that occur upon formation of these complexes., The two structures having ligands at the active sites of both alpha- and, beta-subunits reveal an important new feature, the ordering of, alpha-subunit loop 6 (residues 179-187). Closure of loop 6 isolates the, active site of the alpha-subunit from solvent and results in interaction, between alphaThr183 and the catalytic residue alphaAsp60. Other, conformational differences between the wild type and these two mutant, structures include a rigid-body rotation of the alpha-subunit of, approximately 5 degrees relative to the beta-subunit and large movements, of part of the beta-subunit (residues 93-189) toward the rest of the, beta-subunit. Much smaller differences are observed in the betaK87T-Ser, structure. Remarkably, binding of tryptophan to the beta active site, results in conformational changes very similar to those observed in the, betaK87T-Ser-GP and betaK87T-Ser-IPP structures, with exception of the, disordered alpha-subunit loop 6. These large-scale changes, the closure of, loop 6, and the movements of a small number of side chains in the, alpha-beta interaction site provide a structural base for interpreting the, allosteric properties of tryptophan synthase.
About this Structure
2TRS is a Protein complex structure of sequences from Salmonella typhimurium with , and as ligands. Active as Tryptophan synthase, with EC number 4.2.1.20 Known structural/functional Sites: and . Full crystallographic information is available from OCA.
Reference
Crystal structures of a mutant (betaK87T) tryptophan synthase alpha2beta2 complex with ligands bound to the active sites of the alpha- and beta-subunits reveal ligand-induced conformational changes., Rhee S, Parris KD, Hyde CC, Ahmed SA, Miles EW, Davies DR, Biochemistry. 1997 Jun 24;36(25):7664-80. PMID:9201907
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