Structure of the nucleotide-binding subunit B of the energy producer A1A0 ATP synthase in complex with adenosine diphosphate

✍ Scribed by Kumar, Anil ;Manimekalai, Malathy Sony Subramanian ;Grüber, Gerhard

• Publisher: International Union of Crystallography
• Year: 2008
• Tongue: English
• Weight: 648 KB
• Volume: 64
• Category: Article
• ISSN: 0907-4449
• DOI: 10.1107/s090744490802790x

✦ Synopsis

A 1 A 0 ATP synthases are the major energy producers in archaea. Like the related prokaryotic and eukaryotic F 1 F 0 ATP synthases, they are responsible for most of the synthesis of adenosine triphosphate. The catalytic events of A 1 A 0 ATP synthases take place inside the A 3 B 3 hexamer of the A 1 domain. Recently, the crystallographic structure of the nucleotide-free subunit B of Methanosarcina mazei Go ¨1 A 1 A 0 ATP synthase has been determined at 1.5 A ˚resolution.

To understand more about the nucleotide-binding mechanism, a protocol has been developed to crystallize the subunit B-ADP complex. The crystallographic structure of this complex has been solved at 2.7 A ˚resolution. The ADP occupies a position between the essential phosphate-binding loop and amino-acid residue Phe149, which are involved in the binding of the antibiotic efrapeptin in the related F 1 F 0 ATP synthases. This trapped ADP location is about 13 A ˚distant from its final binding site and is therefore called the transition ADP-binding position. In the trapped ADP position the structure of subunit B adopts a different conformation, mainly in its C-terminal domain and also in the final nucleotide-binding site of the central -domain. This atomic model provides insight into how the substrate enters into the nucleotide-binding protein and thereby into the catalytic A 3 B 3 domain.