Structural and Phylogenetic Analysis of Rhodobacter capsulatus NifF: Uncovering General Features of Nitrogen-fixation (nif)-Flavodoxins

PEREZ-DORADO, INMACULADA; BORTOLOTTI, ANA; CORTEZ NÉSTOR; HERMOSO, JUAN A.

INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

MOLECULAR DIVERSITY PRESERVATION INTERNATIONAL-MDPI

Lugar: Basel; Año: 2013 vol. 14 p. 1152 - 1163

1422-0067

Analysis of the crystal structure of NifF from Rhodobacter capsulatus and itshomologues reported so far reflects the existence of unique structural features in nifflavodoxins: a leucine at the re face of the isoalloxazine, an eight-residue insertion at theC-terminus of the 50?s loop and a remarkable difference in the electrostatic potentialsurface with respect to non-nif flavodoxins. A phylogenetic study on 64 sequences from 52bacterial species revealed four clusters, including different functional prototypes,correlating the previously defined as ?short-chain? with the firmicutes flavodoxins and the?long-chain? with gram-negative species. The comparison of Rhodobacter NifF structurewith other bacterial flavodoxin prototypes discloses the concurrence of specific features ofthese functional electron donors to nitrogenase