1WC6

Soluble adenylyl cyclase CyaC from S. platensis in complex with Rp- ATPalphaS in presence of bicarbonate

1WC6 の概要

• エントリーDOI: 10.2210/pdb1wc6/pdb
• 関連するPDBエントリー: 1WC0 1WC1 1WC3 1WC4 1WC5
• 分子名称: ADENYLATE CYCLASE, ADENOSINE-5'-RP-ALPHA-THIO-TRIPHOSPHATE, MAGNESIUM ION, ... (4 entities in total)
• 機能のキーワード: cyclase, soluble adenylyl cyclase, camp signaling, lyase
• 由来する生物種: SPIRULINA PLATENSIS
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 76468.01

構造登録者

Steegborn, C.,Litvin, T.N.,Levin, L.R.,Buck, J.,Wu, H. (登録日: 2004-11-08, 公開日: 2004-12-20, 最終更新日: 2024-05-08)

主引用文献

Steegborn, C.,Litvin, T.N.,Levin, L.R.,Buck, J.,Wu, H.
Bicarbonate Activation of Adenylyl Cyclase Via Promotion of Catalytic Active Site Closure and Metal Recruitment
Nat.Struct.Mol.Biol., 12:32-, 2005

PubMed Abstract: In an evolutionarily conserved signaling pathway, 'soluble' adenylyl cyclases (sACs) synthesize the ubiquitous second messenger cyclic adenosine 3',5'-monophosphate (cAMP) in response to bicarbonate and calcium signals. Here, we present crystal structures of a cyanobacterial sAC enzyme in complex with ATP analogs, calcium and bicarbonate, which represent distinct catalytic states of the enzyme. The structures reveal that calcium occupies the first ion-binding site and directly mediates nucleotide binding. The single ion-occupied, nucleotide-bound state defines a novel, open adenylyl cyclase state. In contrast, bicarbonate increases the catalytic rate by inducing marked active site closure and recruiting a second, catalytic ion. The phosphates of the bound substrate analogs are rearranged, which would facilitate product formation and release. The mechanisms of calcium and bicarbonate sensing define a reaction pathway involving active site closure and metal recruitment that may be universal for class III cyclases.

PubMed: 15619637
DOI: 10.1038/NSMB880

実験手法

X-RAY DIFFRACTION (2.51 Å)