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PDBsum entry 4m7g
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References listed in PDB file
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Key reference
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Title
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Conformational flexibility in the catalytic triad revealed by the high-Resolution crystal structure of streptomyces erythraeus trypsin in an unliganded state.
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Authors
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E.Blankenship,
K.Vukoti,
M.Miyagi,
D.T.Lodowski.
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Ref.
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Acta Crystallogr D Biol Crystallogr, 2014,
70,
833-840.
[DOI no: ]
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PubMed id
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Abstract
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With more than 500 crystal structures determined, serine proteases make up
greater than one-third of all proteases structurally examined to date, making
them among the best biochemically and structurally characterized enzymes.
Despite the numerous crystallographic and biochemical studies of trypsin and
related serine proteases, there are still considerable shortcomings in the
understanding of their catalytic mechanism. Streptomyces erythraeus trypsin
(SET) does not exhibit autolysis and crystallizes readily at physiological pH;
hence, it is well suited for structural studies aimed at extending the
understanding of the catalytic mechanism of serine proteases. While X-ray
crystallographic structures of this enzyme have been reported, no coordinates
have ever been made available in the Protein Data Bank. Based on this, and
observations on the extreme stability and unique properties of this particular
trypsin, it was decided to crystallize it and determine its structure. Here, the
first sub-angstrom resolution structure of an unmodified, unliganded trypsin
crystallized at physiological pH is reported. Detailed structural analysis
reveals the geometry and structural rigidity of the catalytic triad in the
unoccupied active site and comparison to related serine proteases provides a
context for interpretation of biochemical studies of catalytic mechanism and
activity.
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