5NLA

Crystal structure of the AraC-like transcriptional activator CuxR

Summary for 5NLA

• Entry DOI: 10.2210/pdb5nla/pdb
• Descriptor: Putative transcriptional regulator TRANSCRIPTION REGULATOR protein (2 entities in total)
• Functional Keywords: transcription, polysaccharide, c-di-gmp
• Biological source: Rhizobium meliloti (strain 1021) (Ensifer meliloti)
• Total number of polymer chains: 1
• Total formula weight: 42692.02

Authors

Steinchen, W.M.,Altegoer, F.,Bange, G. (deposition date: 2017-04-04, release date: 2017-05-31, Last modification date: 2024-05-08)

Primary citation

Schaper, S.,Steinchen, W.,Krol, E.,Altegoer, F.,Skotnicka, D.,Sgaard-Andersen, L.,Bange, G.,Becker, A.
AraC-like transcriptional activator CuxR binds c-di-GMP by a PilZ-like mechanism to regulate extracellular polysaccharide production.
Proc. Natl. Acad. Sci. U.S.A., 114:E4822-E4831, 2017

PubMed Abstract: Cyclic dimeric GMP (c-di-GMP) has emerged as a key regulatory player in the transition between planktonic and sedentary biofilm-associated bacterial lifestyles. It controls a multitude of processes including production of extracellular polysaccharides (EPSs). The PilZ domain, consisting of an N-terminal "RxxxR" motif and a β-barrel domain, represents a prototype c-di-GMP receptor. We identified a class of c-di-GMP-responsive proteins, represented by the AraC-like transcription factor CuxR in plant symbiotic α-proteobacteria. In , CuxR stimulates transcription of an EPS biosynthesis gene cluster at elevated c-di-GMP levels. CuxR consists of a Cupin domain, a helical hairpin, and bipartite helix-turn-helix motif. Although unrelated in sequence, the mode of c-di-GMP binding to CuxR is highly reminiscent to that of PilZ domains. c-di-GMP interacts with a conserved N-terminal RxxxR motif and the Cupin domain, thereby promoting CuxR dimerization and DNA binding. We unravel structure and mechanism of a previously unrecognized c-di-GMP-responsive transcription factor and provide insights into the molecular evolution of c-di-GMP binding to proteins.

PubMed: 28559336
DOI: 10.1073/pnas.1702435114

Experimental method

X-RAY DIFFRACTION (2.7 Å)