2pi8
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Crystal structures of an inactive mutant (D308A) of the lytic | + | Crystal structures of an inactive mutant (D308A) of the lytic transglycosylase MltA from Escherichia coli have been determined in two different apo-forms, as well as in complex with the substrate analogue chitohexaose. The chitohexaose binds with all six saccharide residues in the active site groove, with an intact glycosidic bond at the bond cleavage center. Its binding induces a large reorientation of the two structural domains in MltA, narrowing the active site groove and allowing tight interactions of the oligosaccharide with residues from both domains. The structures identify residues in MltA with key roles in the binding and recognition of peptidoglycan and confirm that Asp-308 is the single catalytic residue, acting as a general acid/base. Moreover, the structures suggest that catalysis involves a high energy conformation of the scissile glycosidic linkage and that the putative oxocarbenium ion intermediate is stabilized by the dipole moment of a nearby alpha-helix. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Barends, T | + | [[Category: Barends, T R.M.]] |
| - | [[Category: Dijkstra, B | + | [[Category: Dijkstra, B W.]] |
| - | [[Category: Straaten, K | + | [[Category: Straaten, K E.van.]] |
| - | [[Category: Thunnissen, A | + | [[Category: Thunnissen, A M.W H.]] |
[[Category: PO4]] | [[Category: PO4]] | ||
[[Category: double-psi beta-barrel; protein-sugar complex; lytic transglycosylase]] | [[Category: double-psi beta-barrel; protein-sugar complex; lytic transglycosylase]] | ||
[[Category: hydrolase]] | [[Category: hydrolase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:29:45 2008'' |
Revision as of 16:29, 21 February 2008
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Crystal structure of E. coli MltA with bound chitohexaose
Overview
Crystal structures of an inactive mutant (D308A) of the lytic transglycosylase MltA from Escherichia coli have been determined in two different apo-forms, as well as in complex with the substrate analogue chitohexaose. The chitohexaose binds with all six saccharide residues in the active site groove, with an intact glycosidic bond at the bond cleavage center. Its binding induces a large reorientation of the two structural domains in MltA, narrowing the active site groove and allowing tight interactions of the oligosaccharide with residues from both domains. The structures identify residues in MltA with key roles in the binding and recognition of peptidoglycan and confirm that Asp-308 is the single catalytic residue, acting as a general acid/base. Moreover, the structures suggest that catalysis involves a high energy conformation of the scissile glycosidic linkage and that the putative oxocarbenium ion intermediate is stabilized by the dipole moment of a nearby alpha-helix.
About this Structure
2PI8 is a Single protein structure of sequence from Escherichia coli with as ligand. Full crystallographic information is available from OCA.
Reference
Structure of Escherichia coli Lytic transglycosylase MltA with bound chitohexaose: implications for peptidoglycan binding and cleavage., van Straaten KE, Barends TR, Dijkstra BW, Thunnissen AM, J Biol Chem. 2007 Jul 20;282(29):21197-205. Epub 2007 May 14. PMID:17502382
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