High resolution crystal structure of Rubrivivax gelatinosus cytochrome c'.
The structure of the cytochrome c' from the purple non-sulfur phototrophic bacterium Rubrivivax gelatinosus was determined using two crystals grown independently at pH 6.3 and pH 8. The resolution attained for the two structures (1.29 A and 1.50 A for the crystals at high and low pH, respectively) is the highest to date for this class of proteins. The two structures were compared in detail in an attempt to investigate the influence of pH on the geometry of the haem and of the coordination environment of the Fe(III) ion. However, while the results suggest some small propensity for the movement of the metal atom out of the plane of the haem ring upon pH increase, the accuracy of the measurements at these two pH below the pK of the axial histidine is not sufficient to provide hard evidence of a shift in the iron position and associated changes.
Benini
Stefano
S
York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York, YO10 5YW, United Kingdom.
Rypniewski
Wojciech R
WR
Wilson
Keith S
KS
Ciurli
Stefano
S
D020562:Betaproteobacteria / Q000737:chemistry*; D018360:Crystallography, X-Ray; D045305:Cytochromes c' / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular
D045305:Cytochromes c'