Essential histidine and tryptophan residues in CcsA, a system II polytopic cytochrome c biogenesis protein.

@article{Hamel2003EssentialHA,
  title={Essential histidine and tryptophan residues in CcsA, a system II polytopic cytochrome c biogenesis protein.},
  author={Patrice Paul Hamel and Beth Welty Dreyfuss and Zhiyi Xie and St{\'e}phane T. Gabilly and Sabeeha Merchant},
  journal={The Journal of biological chemistry},
  year={2003},
  volume={278 4},
  pages={2593-603}
}
Three distinct systems (I, II, and III) for catalysis of heme attachment to c-type apocytochromes are known. The CcsA and Ccs1 proteins are required in system II for the assembly of bacterial and plastid cytochromes c. A tryptophan-rich signature motif (WWD), also occurring in CcmC and CcmF found in system I, and three histidinyl residues, all strictly conserved in CcsA suggest a function in heme handling. Topological analysis of plastid CcsA in bacteria using the PhoA and LacZalpha reporters… CONTINUE READING