2big

Radiation damage of the Schiff base in phosphoserine aminotransferase (structure I)

spinqualitylabelsall models 2big, resolution 1.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2big is a 2 chain structure with sequence from Alkalihalobacillus alcalophilus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.3Å Ligands: CL, MG, PEG, PGE, PLP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function SERC_ALKAL Catalyzes the reversible conversion of 3-phosphohydroxypyruvate to phosphoserine and of 3-hydroxy-2-oxo-4-phosphonooxybutanoate to phosphohydroxythreonine. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed 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. 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 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Phosphoserine aminotransferase

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