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PDBsum entry 2ecf
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References listed in PDB file
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Key reference
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Title
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Dipeptidyl aminopeptidase IV from stenotrophomonas maltophilia exhibits activity against a substrate containing a 4-Hydroxyproline residue.
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Authors
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Y.Nakajima,
K.Ito,
T.Toshima,
T.Egawa,
H.Zheng,
H.Oyama,
Y.F.Wu,
E.Takahashi,
K.Kyono,
T.Yoshimoto.
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Ref.
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J Bacteriol, 2008,
190,
7819-7829.
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PubMed id
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Abstract
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The crystal structure of dipeptidyl aminopeptidase IV from Stenotrophomonas
maltophilia was determined at 2.8-A resolution by the multiple isomorphous
replacement method, using platinum and selenomethionine derivatives. The
crystals belong to space group P4(3)2(1)2, with unit cell parameters a = b =
105.9 A and c = 161.9 A. Dipeptidyl aminopeptidase IV is a homodimer, and the
subunit structure is composed of two domains, namely, N-terminal beta-propeller
and C-terminal catalytic domains. At the active site, a hydrophobic pocket to
accommodate a proline residue of the substrate is conserved as well as those of
mammalian enzymes. Stenotrophomonas dipeptidyl aminopeptidase IV exhibited
activity toward a substrate containing a 4-hydroxyproline residue at the second
position from the N terminus. In the Stenotrophomonas enzyme, one of the
residues composing the hydrophobic pocket at the active site is changed to
Asn611 from the corresponding residue of Tyr631 in the porcine enzyme, which
showed very low activity against the substrate containing 4-hydroxyproline. The
N611Y mutant enzyme was generated by site-directed mutagenesis. The activity of
this mutant enzyme toward a substrate containing 4-hydroxyproline decreased to
30.6% of that of the wild-type enzyme. Accordingly, it was considered that
Asn611 would be one of the major factors involved in the recognition of
substrates containing 4-hydroxyproline.
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