The crystal structure of D-lactate dehydrogenase, a peripheral membrane respiratory enzyme.Dym, O., Pratt, E.A., Ho, C., Eisenberg, D.
(2000) Proc Natl Acad Sci U S A 97: 9413-9418
- PubMed: 10944213
- DOI: https://doi.org/10.1073/pnas.97.17.9413
- Primary Citation of Related Structures:
- PubMed Abstract:
d-Lactate dehydrogenase (d-LDH) of Escherichia coli is a peripheral membrane respiratory enzyme involved in electron transfer, located on the cytoplasmic side of the inner membrane. d-LDH catalyzes the oxidation of d-lactate to pyruvate, which is coupled to transmembrane transport of amino acids and sugars. Here we describe the crystal structure at 1.9 A resolution of the three domains of d-LDH: the flavin adenine dinucleotide (FAD)-binding domain, the cap domain, and the membrane-binding domain. The FAD-binding domain contains the site of d-lactate reduction by a noncovalently bound FAD cofactor and has an overall fold similar to other members of a recently discovered FAD-containing family of proteins. This structural similarity extends to the cap domain as well. The most prominent difference between d-LDH and the other members of the FAD-containing family is the membrane-binding domain, which is either absent in some of these proteins or differs significantly. The d-LDH membrane-binding domain presents an electropositive surface with six Arg and five Lys residues, which presumably interacts with the negatively charged phospholipid head groups of the membrane. Thus, d-LDH appears to bind the membrane through electrostatic rather than hydrophobic forces.
Department of Energy Laboratory of Structural Biology and Molecular Medicine, University of California, Los Angeles 90095, USA.