Complexation of CcmB with CcmACD safeguards heme translocation for cytochrome c maturation  

作　　者：Yuanyou Xu Wei Wang Qianrou Zhang Sirui Han Jiahao Wang Shihua Wu Haichun Gao 

机构地区：[1]Institute of Microbiology and College of Life Sciences,Zhejiang University,Hangzhou,China

出　　处：《mLife》2025年第1期29-44,共16页微生物(英文)

基　　金：supported by the National Natural Science Foundation of China(31930003 and 41976087);the National Key R&D Program of China(2018YFA0901300).

摘　　要：Cytochrome c maturation(CCM),a posttranslational modification involving covalent attachment of heme to polypeptides(apocyt c),is essential for the activity and cellular function of cytochromes c.Here,we identify and substantiate CcmB as heme translocase in bacteria.When in excess,CcmB expels intracellular heme into the periplasm and thus is detrimental to the cell.We then show that complexation with CcmACD ensures heme translocated by CcmB to be used for CCM only.Moreover,structural analysis and atomistic molecular dynamics simulations reveal that CcmB absorbs heme from the membrane to a heme pocket formed in the dimer interface of the transmembrane helix-bundles.These data,collectively by providing detailed insights into the conformational landscape of CcmB during heme entry,fill in the missing link in our understanding of the heme translocation for CCM.

关 键 词：CcmABCD cytochrome c cytochrome c biosynthesis HEME heme translocation 

分 类 号：Q55[生物学—生物化学]