PDBsum entry 1leh

Oxidoreductase

PDB id: 1leh

Contents

Protein chains

364 a.a. *

Waters ×116

* Residue conservation analysis

PDB id:

1leh

Name:

Oxidoreductase

Title:

Leucine dehydrogenase from bacillus sphaericus

Structure:

Leucine dehydrogenase. Chain: a, b. Ec: 1.4.1.9

Source:

Lysinibacillus sphaericus. Organism_taxid: 1421. Atcc: 4525

Biol. unit:

Octamer (from PDB file)

Resolution:

2.20Å R-factor: 0.201

Authors:

P.J.Baker,A.P.Turnbull,S.E.Sedelnikova,T.J.Stillman,D.W.Rice

Key ref:

P.J.Baker et al. (1995). A role for quaternary structure in the substrate specificity of leucine dehydrogenase. Structure, 3, 693-705. PubMed id: 8591046 DOI: 10.1016/S0969-2126(01)00204-0

Date:

09-Jun-95 Release date: 23-Dec-96

Protein chains

Q7SIB4  (Q7SIB4_LYSSH) -  Oxidoreductase from Lysinibacillus sphaericus

Seq: 364 a.a.

Struc: 364 a.a.

Enzyme reactions

• Enzyme class: E.C.1.4.1.9 - leucine dehydrogenase.
• Reaction: L-leucine + NAD⁺ + H2O = 4-methyl-2-oxopentanoate + NH4⁺ + NADH + H⁺

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1016/S0969-2126(01)00204-0

Structure 3:693-705 (1995)

PubMed id: 8591046

A role for quaternary structure in the substrate specificity of leucine dehydrogenase.

P.J.Baker, A.P.Turnbull, S.E.Sedelnikova, T.J.Stillman, D.W.Rice.

ABSTRACT

BACKGROUND: Glutamate, phenylalanine and leucine dehydrogenases catalyze the NAD(P)(+)-linked oxidative deamination of L-amino acids to the corresponding 2-oxoacids, and sequence homology between these enzymes clearly indicates the existence of an enzyme superfamily related by divergent evolution. We have undertaken structural studies on a number of members of this family in order to investigate the molecular basis of their differential amino acid specificity. RESULTS: We have solved the X-ray structure of the leucine dehydrogenase from Bacillus sphaericus to a resolution of 2.2 A. Each subunit of this octameric enzyme contains 364 amino acids and folds into two domains, separated by a deep cleft. The nicotinamide ring of the NAD+ cofactor binds deep in this cleft, which is thought to close during the hydride transfer step of the catalytic cycle. CONCLUSIONS: Comparison of the structure of leucine dehydrogenase with a hexameric glutamate dehydrogenase has shown that these two enzymes share a related fold and possess a similar catalytic chemistry. A mechanism for the basis of the differential amino acid specificity between these enzymes involves point mutations in the amino acid side-chain specificity pocket and subtle changes in the shape of this pocket caused by the differences in quaternary structure.

Selected figure(s)

Figure 2.
Figure 2. Stereo diagrams of a single subunit of LeuDH. The organization of the subunit into two domains, separated by a deep cleft, can be seen. In this view the fourfold axis of the LeuDH octamer runs vertically. (a) Schematic representation with the strands and helices numbered. (b) Cα trace with every tenth residue indicated by a black dot. Figure 2. Stereo diagrams of a single subunit of LeuDH. The organization of the subunit into two domains, separated by a deep cleft, can be seen. In this view the fourfold axis of the LeuDH octamer runs vertically. (a) Schematic representation with the strands and helices numbered. (b) Cα trace with every tenth residue indicated by a black dot. (Figure prepared using MOLSCRIPT [[3]41].)

Figure 4.
Figure 4. Stereo ribbon diagram illustrating the interactions around the fourfold axis in LeuDH. Two monomers are shown (red and green), viewed down the non-crystallographic twofold axis which relates pairs of dimers, with the fourfold axis vertical. Figure 4. Stereo ribbon diagram illustrating the interactions around the fourfold axis in LeuDH. Two monomers are shown (red and green), viewed down the non-crystallographic twofold axis which relates pairs of dimers, with the fourfold axis vertical. (Figure prepared using FRODO [[3]38].)

The above figures are reprinted by permission from Cell Press: Structure (1995, 3, 693-705) copyright 1995.

Figures were selected by an automated process.