Structural changes at the surface of cytochrome c oxidase alter the proton-pumping stoichiometry

Content Provider	Scilit
Author	Berg, Johan Liu, Jian Svahn, Emelie Ferguson-Miller, Shelagh Brzezinski, Peter
Copyright Year	2019
Description	Journal: Biochimica Et Biophysica Acta (bba) - Bioenergetics Data from earlier studies showed that minor structural changes at the surface of cytochrome c oxidase, in one of the proton-input pathways (the D pathway), result in dramatically decreased activity and a lower proton-pumping stoichiometry. To further investigate how changes around the D pathway orifice influence functionality of the enzyme, here we modified the nearby C-terminal loop of subunit I of the Rhodobacter sphaeroides cytochrome c oxidase. Removal of 16 residues from this flexible surface loop resulted in a decrease in the proton-pumping stoichiometry to <50% of that of the wild-type enzyme. Replacement of the protonatable residue Glu552, part of the same loop, by an Ala, resulted in a similar decrease in the proton-pumping stoichiometry without loss of the $O_{2}$-reduction activity or changes in the proton-uptake kinetics. The data show that minor structural changes at the orifice of the D pathway, at a distance of ~40 Å from the proton gate of cytochrome c oxidase, may alter the proton-pumping stoichiometry of the enzyme.
Related Links	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6943178/pdf
Ending Page	148116
Page Count	1
Starting Page	148116
ISSN	00052728
e-ISSN	18792650
DOI	10.1016/j.bbabio.2019.148116
Journal	Biochimica Et Biophysica Acta (bba) - Bioenergetics
Issue Number	2
Volume Number	1861
Language	English
Publisher	Elsevier BV
Publisher Date	2019-11-14
Access Restriction	Open
Subject Keyword	Journal: Biochimica Et Biophysica Acta (bba) - Bioenergetics Biochemistry and Molecular Biology Mycobacterium Smegmatis Respiratory Chain Electron Transfer
Content Type	Text
Resource Type	Article
Subject	Cell Biology Biochemistry Biophysics