2bi5: Difference between revisions
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==Overview== | ==Overview== | ||
The X-ray susceptibility of the lysine-pyridoxal-5'-phosphate Schiff base | The X-ray susceptibility of the lysine-pyridoxal-5'-phosphate Schiff base in Bacillus alcalophilus phosphoserine aminotransferase has been investigated using crystallographic data collected at 100 K to 1.3 A resolution, complemented by on-line spectroscopic studies. X-rays induce deprotonation of the internal aldimine, changes in the Schiff base conformation, displacement of the cofactor molecule, and disruption of the Schiff base linkage between pyridoxal-5'-phosphate and the Lys residue. Analysis of the "undamaged" structure reveals a significant chemical strain on the internal aldimine bond that leads to a pronounced geometrical distortion of the cofactor. However, upon crystal exposure to the X-rays, the strain and distortion are relaxed and eventually diminished when the total absorbed dose has exceeded 4.7 x 10(6) Ggamma. Our data provide new insights into the enzymatic activation of pyridoxal-5'-phosphate and suggest that special care should be taken while using macromolecular crystallography to study details in strained active sites. | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: Phosphoserine transaminase]] | [[Category: Phosphoserine transaminase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Dubnovitsky, A | [[Category: Dubnovitsky, A P.]] | ||
[[Category: Papageorgiou, A | [[Category: Papageorgiou, A C.]] | ||
[[Category: Popov, A | [[Category: Popov, A N.]] | ||
[[Category: Ravelli, R | [[Category: Ravelli, R B.G.]] | ||
[[Category: 1PE]] | [[Category: 1PE]] | ||
[[Category: CL]] | [[Category: CL]] | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
''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 16:38:06 2008'' | ||
Revision as of 17:38, 21 February 2008
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RADIATION DAMAGE OF THE SCHIFF BASE IN PHOSPHOSERINE AMINOTRANSFERASE (STRUCTURE E)
OverviewOverview
The X-ray susceptibility of the lysine-pyridoxal-5'-phosphate Schiff base in Bacillus alcalophilus phosphoserine aminotransferase has been investigated using crystallographic data collected at 100 K to 1.3 A resolution, complemented by on-line spectroscopic studies. X-rays induce deprotonation of the internal aldimine, changes in the Schiff base conformation, displacement of the cofactor molecule, and disruption of the Schiff base linkage between pyridoxal-5'-phosphate and the Lys residue. Analysis of the "undamaged" structure reveals a significant chemical strain on the internal aldimine bond that leads to a pronounced geometrical distortion of the cofactor. However, upon crystal exposure to the X-rays, the strain and distortion are relaxed and eventually diminished when the total absorbed dose has exceeded 4.7 x 10(6) Ggamma. Our data provide new insights into the enzymatic activation of pyridoxal-5'-phosphate and suggest that special care should be taken while using macromolecular crystallography to study details in strained active sites.
About this StructureAbout this Structure
2BI5 is a Single protein structure of sequence from Bacillus alcalophilus with , , , and as ligands. Active as Phosphoserine transaminase, with EC number 2.6.1.52 Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
Strain relief at the active site of phosphoserine aminotransferase induced by radiation damage., Dubnovitsky AP, Ravelli RB, Popov AN, Papageorgiou AC, Protein Sci. 2005 Jun;14(6):1498-507. Epub 2005 May 9. PMID:15883191
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