The β-hairpin region of cyanobacterial F1-ATPase γ subunit plays a regulatory role in the enzyme activity.

The β-hairpin region of cyanobacterial F1-ATPase γ subunit plays a regulatory role in the enzyme activity.
Biochem J. 2019 Jun 04;:
Authors: Akiyama K, Kondo K, Inabe K, Murakami S, Wakabayashi KI, Hisabori T
Abstract
The γ subunit of cyanobacterial and chloroplast ATP synthase, the rotary shaft of F1-ATPase, equips a specific insertion region that is only observed in photosynthetic organisms. This region plays a physiologically pivotal role in enzyme regulation, such as in ADP inhibition and redox response. Recently solved crystal structures of the γ subunit of F1-ATPase from photosynthetic organisms revealed that the insertion region forms a β-hairpin structure, which is positioned along the central stalk. The structure-function relationship of this specific region was studied by constraining the expected conformational change in this region caused by the formation of a disulfide bond between Cys residues introduced on the central stalk and this β-hairpin structure. This fixation of the β-hairpin region in the α3β3γ complex affects both ADP inhibition and the binding of the ε subunit to the complex, indicating the critical role that the β-hairpin region plays as a regulator of the enzyme. This role must be important for the maintenance of the intracellular ATP levels in photosynthetic organisms.
PMID: 31164401 [PubMed - as supplied by publisher]

Source: The Biochemical Journal - June 3, 2019 Category: Biochemistry Authors: Akiyama K, Kondo K, Inabe K, Murakami S, Wakabayashi KI, Hisabori T Tags: Biochem J Source Type: research