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PDBsum entry 4wl2
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References listed in PDB file
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Key reference
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Title
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Structural analysis of a penicillin V acylase from pectobacterium atrosepticum confirms the importance of two trp residues for activity and specificity.
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Authors
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V.S.Avinash,
P.Panigrahi,
D.Chand,
A.Pundle,
C.G.Suresh,
S.Ramasamy.
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Ref.
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J Struct Biol, 2016,
193,
85-94.
[DOI no: ]
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PubMed id
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Note: In the PDB file this reference is
annotated as "TO BE PUBLISHED". The citation details given above have
been manually determined.
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Abstract
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Penicillin V acylases (PVA) catalyze the deacylation of the beta-lactam
antibiotic phenoxymethylpenicillin (Pen V). They are members of the Ntn
hydrolase family and possess an N-terminal cysteine as the main catalytic
nucleophile residue. They form the evolutionarily related cholylglycine
hydrolase (CGH) group which includes bile salt hydrolases (BSH) responsible for
bile deconjugation. Even though a few PVA and BSH structures have been reported,
no structure of a functional PVA from Gram-negative bacteria is available. Here,
we report the crystal structure of a highly active PVA from Gram-negative
Pectobacterium atrosepticum (PaPVA) at 2.5Å resolution. Structural comparison
with PVAs from Gram-positive bacteria revealed that PaPVA had a distinctive
tetrameric structure and active site organization. In addition, mutagenesis of
key active site residues and biochemical characterization of the resultant
variants elucidated the role of these residues in substrate binding and
catalysis. The importance of residue Trp23 and Trp87 side chains in binding and
correct positioning of Pen V by PVAs was confirmed using mutagenesis and
substrate docking with a 15ns molecular dynamics simulation. These results
establish the unique nature of Gram-negative CGHs and necessitate further
research about their substrate spectrum.
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