6ZZ9

Crystal structure of CbpB from Streptococcus agalactiae

Summary for 6ZZ9

• Entry DOI: 10.2210/pdb6zz9/pdb
• Descriptor: CBS domain-containing protein, SULFATE ION, PLATINUM (II) ION (3 entities in total)
• Functional Keywords: cbs, c-di-amp, signaling protein
• Biological source: Streptococcus agalactiae
• Total number of polymer chains: 2
• Total formula weight: 40375.49

Authors

Mechaly, A.E.,Covaleda-Cortes, G.,Kaminski, P.A. (deposition date: 2020-08-04, release date: 2021-08-18, Last modification date: 2024-06-19)

Primary citation

Covaleda-Cortes, G.,Mechaly, A.,Brissac, T.,Baehre, H.,Devaux, L.,England, P.,Raynal, B.,Hoos, S.,Gominet, M.,Firon, A.,Trieu-Cuot, P.,Kaminski, P.A.
The c-di-AMP-binding protein CbpB modulates the level of ppGpp alarmone in Streptococcus agalactiae.
Febs J., 2023

PubMed Abstract: Cyclic di-AMP is an essential signalling molecule in Gram-positive bacteria. This second messenger regulates the osmotic pressure of the cell by interacting directly with the regulatory domains, either RCK_C or CBS domains, of several potassium and osmolyte uptake membrane protein systems. Cyclic di-AMP also targets stand-alone CBS domain proteins such as DarB in Bacillus subtilis and CbpB in Listeria monocytogenes. We show here that the CbpB protein of Group B Streptococcus binds c-di-AMP with a very high affinity. Crystal structures of CbpB reveal the determinants of binding specificity and significant conformational changes occurring upon c-di-AMP binding. Deletion of the cbpB gene alters bacterial growth in low potassium conditions most likely due to a decrease in the amount of ppGpp caused by a loss of interaction between CbpB and Rel, the GTP/GDP pyrophosphokinase.

PubMed: 36629470
DOI: 10.1111/febs.16724

Experimental method

X-RAY DIFFRACTION (2.644 Å)