4P00

Bacterial Cellulose Synthase in complex with cyclic-di-GMP and UDP

Summary for 4P00

• Entry DOI: 10.2210/pdb4p00/pdb
• Related: 4HG6 4P02
• Descriptor: Cellulose Synthase A subunit, Cellulose Synthase B subunit, unidentified peptide, ... (9 entities in total)
• Functional Keywords: membrane protein, cellulose biosynthesis, biofilm, cyclic-di-gmp, transferase
• Biological source: Rhodobacter sphaeroides; More
• Total number of polymer chains: 3
• Total formula weight: 173390.23

Authors

Morgan, J.L.W.,McNamara, J.T.,Zimmer, J. (deposition date: 2014-02-19, release date: 2014-04-09, Last modification date: 2024-10-23)

Primary citation

Morgan, J.L.,McNamara, J.T.,Zimmer, J.
Mechanism of activation of bacterial cellulose synthase by cyclic di-GMP.
Nat.Struct.Mol.Biol., 21:489-496, 2014

PubMed Abstract: The bacterial signaling molecule cyclic di-GMP (c-di-GMP) stimulates the synthesis of bacterial cellulose, which is frequently found in biofilms. Bacterial cellulose is synthesized and translocated across the inner membrane by a complex of cellulose synthase BcsA and BcsB subunits. Here we present crystal structures of the c-di-GMP-activated BcsA-BcsB complex. The structures reveal that c-di-GMP releases an autoinhibited state of the enzyme by breaking a salt bridge that otherwise tethers a conserved gating loop that controls access to and substrate coordination at the active site. Disrupting the salt bridge by mutagenesis generates a constitutively active cellulose synthase. Additionally, the c-di-GMP-activated BcsA-BcsB complex contains a nascent cellulose polymer whose terminal glucose unit rests at a new location above BcsA's active site and is positioned for catalysis. Our mechanistic insights indicate how c-di-GMP allosterically modulates enzymatic functions.

PubMed: 24704788
DOI: 10.1038/nsmb.2803

Experimental method

X-RAY DIFFRACTION (3.2 Å)