Crystal structure of Azotobacter cytochrome c5 at 2.5 A resolution.Carter, D.C., Melis, K.A., O'Donnell, S.E., Burgess, B.K., Furey Jr., W.R., Wang, B.C., Stout, C.D.
(1985) J Mol Biol 184: 279-295
- PubMed: 2993632
- DOI: 10.1016/0022-2836(85)90380-8
- Structures With Same Primary Citation
- PubMed Abstract:
- Preliminary Crystallographic Data for Azotobacter Cytochrome C5
(1978) J Mol Biol 126: 105
The crystal structure of cytochrome c5 from Azotobacter vinelandii has been solved and refined to an R value of 0.29 at 2.5 A resolution. The structure of the oxidized protein was solved using a monoclinic crystal form. The structure was solved by mu ...
The crystal structure of cytochrome c5 from Azotobacter vinelandii has been solved and refined to an R value of 0.29 at 2.5 A resolution. The structure of the oxidized protein was solved using a monoclinic crystal form. The structure was solved by multiple isomorphous replacements, re-fit to a solvent-leveled multiple isomorphous replacement map, and refined by restrained least squares. The structure reveals monomers associated about the crystallographic 2-fold axis by hydrophobic contacts at the "exposed heme edge". The overall conformation for the monomer is similar to that of Pseudomonas aeruginosa cytochrome c551. However, relative to a common heme conformation, c5 and c551 differ by an average of 6.8 A over 82 alpha-carbon positions and the propionates of c5 are much more exposed to solvent. The shortest heme--heme contact at the "dimer" interface is 6.3 A (Fe to Fe 16.4 A). Alignment of c5 and c551 shows that the two cytochromes, in spite of sequence differences, have remarkably similar charge distributions. A disulfide stacks on a tyrosine between the N- and C-terminal helices.
Dep. de Física e Biofísica, Instituto de Biociências, UNESP-Universidade Estadual Paulista, Botucatu, São Paulo, Brazil; Instituto Nacional de Ciência e Tecnologia em Toxinas, CNPq, São Paulo, São Paulo, Brazil.