5O3R

Carbon regulatory PII-like protein SbtB from Synechocystis sp. 6803 in complex with AMP

5O3R の概要

• エントリーDOI: 10.2210/pdb5o3r/pdb
• 分子名称: Membrane-associated protein slr1513, ADENOSINE MONOPHOSPHATE, BICARBONATE ION, ... (4 entities in total)
• 機能のキーワード: sbtb, carbon sensing, pii-like, cyanobacteria, signaling protein
• 由来する生物種: Synechocystis sp. PCC 6803
• 細胞内の位置: Cellular thylakoid membrane ; Peripheral membrane protein ; Cytoplasmic side : P73954
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 40769.01

構造登録者

Selim, K.A.,Forchhammer, K.,Albrecht, R.,Hartmann, M.D. (登録日: 2017-05-24, 公開日: 2018-05-16, 最終更新日: 2024-10-23)

主引用文献

Selim, K.A.,Haase, F.,Hartmann, M.D.,Hagemann, M.,Forchhammer, K.
PII-like signaling protein SbtB links cAMP sensing with cyanobacterial inorganic carbon response.
Proc. Natl. Acad. Sci. U.S.A., 115:E4861-E4869, 2018

PubMed Abstract: Cyanobacteria are phototrophic prokaryotes that evolved oxygenic photosynthesis ∼2.7 billion y ago and are presently responsible for ∼10% of total global photosynthetic production. To cope with the evolutionary pressure of dropping ambient CO concentrations, they evolved a CO-concentrating mechanism (CCM) to augment intracellular inorganic carbon (C) levels for efficient CO fixation. However, how cyanobacteria sense the fluctuation in C is poorly understood. Here we present biochemical, structural, and physiological insights into SbtB, a unique P-like signaling protein, which provides new insights into C sensing. SbtB is highly conserved in cyanobacteria and is coexpressed with CCM genes. The SbtB protein from the cyanobacterium sp. PCC 6803 bound a variety of adenosine nucleotides, including the second messenger cAMP. Cocrystal structures unraveled the individual binding modes of trimeric SbtB with AMP and cAMP. The nucleotide-binding pocket is located between the subunit clefts of SbtB, perfectly matching the structure of canonical P proteins. This clearly indicates that proteins of the P superfamily arose from a common ancestor, whose structurally conserved nucleotide-binding pocket has evolved to sense different adenyl nucleotides for various signaling functions. Moreover, we provide physiological and biochemical evidence for the involvement of SbtB in C acclimation. Collectively, our results suggest that SbtB acts as a C sensor protein via cAMP binding, highlighting an evolutionarily conserved role for cAMP in signaling the cellular carbon status.

PubMed: 29735650
DOI: 10.1073/pnas.1803790115

実験手法

X-RAY DIFFRACTION (1.9 Å)