Cloning, heterologous expression, and characterization of recombinant class II cytochromes c from Rhodopseudomonas palustris.
The cytochrome (cyt) c', cyt c(556), and cyt c(2) genes from Rhodopseudomonas palustris have been cloned; recombinant cyt c' and cyt c(556) have been expressed, purified, and characterized. Unlike mitochondrial cyt c, these two proteins are structurally similar to cyt b(562), in which the heme is embedded in a four-helix bundle. The hemes in both recombinant proteins form covalent thioether links to two Cys residues. UV/vis spectra of the Fe(II) and Fe(III) states of the recombinant cyts are identical with those of the corresponding native proteins. Equilibrium unfolding measurements in guanidine hydrochloride solutions confirm that native Fe(II)-cyt c(556) is more stable than the corresponding state of Fe(III)-cyt c(556) (DeltaDeltaG(f)(o) =22 kJ/mol).
McGuirl
Michele A
MA
Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA.
Lee
Jennifer C
JC
Lyubovitsky
Julia G
JG
Thanyakoop
Chalita
C
Richards
John H
JH
Gray
Harry B
HB
Winkler
Jay R
JR
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D003574:Cytochrome c Group / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004269:DNA, Bacterial; D008969:Molecular Sequence Data; D012241:Rhodopseudomonas / Q000201:enzymology*; D013056:Spectrophotometry, Ultraviolet
D003574:Cytochrome c Group; D004269:DNA, Bacterial