PMID- 26898520
OWN - NLM
STAT- MEDLINE
DCOM- 20160818
LR  - 20170806
IS  - 0006-3002 (Print)
IS  - 0006-3002 (Linking)
VI  - 1857
IP  - 8
DP  - 2016 Aug
TI  - The role of the K-channel and the active-site tyrosine in the catalytic mechanism 
      of cytochrome c oxidase.
PG  - 1111-1115
LID - S0005-2728(16)30027-5 [pii]
LID - 10.1016/j.bbabio.2016.02.008 [doi]
AB  - The active site of cytochrome c oxidase (CcO) comprises an oxygen-binding heme, a 
      nearby copper ion (CuB), and a tyrosine residue that is covalently linked to one 
      of the histidine ligands of CuB. Two proton-conducting pathways are observed in 
      CcO, namely the D- and the K-channels, which are used to transfer protons either 
      to the active site of oxygen reduction (substrate protons) or for pumping. Proton 
      transfer through the D-channel is very fast, and its role in efficient transfer 
      of both substrate and pumped protons is well established. However, it has not 
      been fully clear why a separate K-channel is required, apparently for the supply 
      of substrate protons only. In this work, we have analysed the available 
      experimental and computational data, based on which we provide new perspectives 
      on the role of the K-channel. Our analysis suggests that proton transfer in the 
      K-channel may be gated by the protonation state of the active-site tyrosine 
      (Tyr244) and that the neutral radical form of this residue has a more general 
      role in the CcO mechanism than thought previously. This article is part of a 
      Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva 
      del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
CI  - Copyright (c) 2016 Elsevier B.V. All rights reserved.
FAU - Sharma, Vivek
AU  - Sharma V
AD  - Department of Physics, Tampere University of Technology, Tampere FI-33101, 
      Finland; Department of Physics, University of Helsinki, Helsinki, Finland. 
      Electronic address: vivek.sharma@tut.fi.
FAU - Wikstrom, Marten
AU  - Wikstrom M
AD  - Institute of Biotechnology, University of Helsinki, Helsinki, FI-00014, Finland. 
      Electronic address: marten.wikstrom@helsinki.fi.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Review
DEP - 20160217
PL  - Netherlands
TA  - Biochim Biophys Acta
JT  - Biochimica et biophysica acta
JID - 0217513
RN  - 0 (Protons)
RN  - 42HK56048U (Tyrosine)
RN  - 42VZT0U6YR (Heme)
RN  - 4QD397987E (Histidine)
RN  - 789U1901C5 (Copper)
RN  - EC 1.9.3.1 (Electron Transport Complex IV)
SB  - IM
MH  - Animals
MH  - Biocatalysis
MH  - Catalytic Domain
MH  - Cattle
MH  - Copper/*chemistry
MH  - Electron Transport
MH  - Electron Transport Complex IV/*chemistry/genetics/metabolism
MH  - Gene Expression
MH  - Heme/*chemistry
MH  - Histidine/chemistry
MH  - Ion Transport
MH  - Mitochondria/genetics/*metabolism
MH  - *Protons
MH  - Tyrosine/*chemistry/metabolism
OTO - NOTNLM
OT  - Electron transfer
OT  - Neutral tyrosyl radical
OT  - Proton pumping
EDAT- 2016/02/24 06:00
MHDA- 2016/08/19 06:00
CRDT- 2016/02/23 06:00
PHST- 2016/01/13 00:00 [received]
PHST- 2016/02/09 00:00 [revised]
PHST- 2016/02/15 00:00 [accepted]
PHST- 2016/02/23 06:00 [entrez]
PHST- 2016/02/24 06:00 [pubmed]
PHST- 2016/08/19 06:00 [medline]
AID - S0005-2728(16)30027-5 [pii]
AID - 10.1016/j.bbabio.2016.02.008 [doi]
PST - ppublish
SO  - Biochim Biophys Acta. 2016 Aug;1857(8):1111-1115. doi: 
      10.1016/j.bbabio.2016.02.008. Epub 2016 Feb 17.