The dapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase from Haemophilus influenzae contains two active-site histidine residues.
The dapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase from Haemophilus influenzae contains two active-site histidine residues.
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DOI：
10.1007/s00775-008-0418-z
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发表时间：
2009-01
影响因子：
3
通讯作者：
Holz, Richard C.
中科院分区：
文献类型：
--
作者：
Gillner, Danuta M.;Bienvenue, David L.;Nocek, Boguslaw P.;Joachimiak, Andrzej;Zachary, Vincentos;Bennett, Brian;Holz, Richard C.
The catalytic and structural properties of the H67A and H349A altered dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE) from H. influenzae were investigated. Based on sequence alignment with CPG2 both H67 and H349 were predicted to be Zn(II) ligands. Catalytic activity was observed for the H67A altered DapE enzyme which exhibited kcat = 1.5 ± 0.5 sec−1 and Km = 1.4 ± 0.3 mM. No catalytic activity was observed for H349A under the experimental conditions used. The EPR and electronic absorption data indicate that the Co(II) ion bound to H349A-DapE is analogous to WT DapE after the addition of a single Co(II) ion. The addition of one equivalent of Co(II) to H67A altered DapE provides spectra that are very different from the first Co(II) binding site of the WT enzyme, but similar to the second binding site. The EPR and electronic absorption data, in conjunction with the kinetic data, are consistent with the assignment of H67 and H349 as active site metal ligands for the DapE from H. influenzae. Furthermore, the data suggest that H67 is a ligand in the first metal binding site while H349 resides in the second metal binding site. A three-dimensional homology structure of the DapE from H. influenzae was generated using the X-ray crystal structure of the DapE from N. meningitidis as a template and superimposed on the structure of AAP. This homology structure confirms the assignment of H67 and H349 as active site ligands. The superimposition of the homology model of DapE with the dizinc(II) structure of AAP indicates that within 4.0 Å of the Zn(II) binding sites of AAP, all of the amino acid residues of DapE are nearly identical.
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影响因子：
14.9
作者：
Eswar, N;John, B;Sali, A
通讯作者：
Sali, A
影响因子：
2.9
作者：
Bienvenue, DL;Gilner, DM;Holz, RC
通讯作者：
Holz, RC
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2.9
作者：
Crawford, PA;Yang, KW;Crowder, MW
通讯作者：
Crowder, MW
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De Paola, CC;Bennett, B;Petsko, GA
通讯作者：
Petsko, GA
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2.9
作者：
Huntington, KM;Bienvenue, DL;Pei, DH
通讯作者：
Pei, DH