TY  - JOUR
A1  - Witt, Heike
A1  - Malatesta, Francesco
A1  - Nicoletti, Flavia
A1  - Brunori, Maurizio
A1  - Ludwig, Bernd
T1  - Tryptophan 121 of subunit II is the electron entry site to cytochrome-c oxidase in Paracoccus denitrificans. Involvement of a hydrophobic patch in the docking reaction
T2  - Journal of biological chemistry
N2  - To investigate the contribution of hydrophobic residues to the molecular recognition of cytochrome c with cytochrome oxidase, we mutated several hydrophobic amino acids exposed on subunit II of the Paracoccus denitrificans oxidase. KM and kcat values and the bimolecular rate constant were determined under steady- or presteady-state conditions, respectively. We present evidence that Trp-121 which is surrounded by a hydrophobic patch is the electron entry site to oxidase. Mutations in this cluster do not affect the binding of cytochrome c as the KM remains largely unchanged. Rather, the kcat is reduced, proposing that these hydrophobic residues are required for a fine tuning of the redox partners in the initial collisional complex to obtain a configuration optimal for electron transfer.
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/75883
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-758837
SN  - 0021-9258
VL  - 273.1998
IS  - 9
SP  - 5132
EP  - 5136
PB  - American Society for Biochemistry and Molecular Biology Publications
CY  - Bethesda, Md
ER  -