3VX4

Crystal Structure of the Nucleotide-Binding Domain of S. mutans ComA, a Bifunctional ATP-binding Cassette Transporter Involved in the Quorum-sensing Pathway

Summary for 3VX4

• Entry DOI: 10.2210/pdb3vx4/pdb
• Descriptor: Putative ABC transporter, ATP-binding protein ComA, ADENOSINE-5'-TRIPHOSPHATE, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: abc transporter, atp binding, transport protein
• Biological source: Streptococcus mutans
• Total number of polymer chains: 2
• Total formula weight: 61761.87

Authors

Ishii, S.,Yano, T.,Okamoto, A.,Murakawa, T.,Hayashi, H. (deposition date: 2012-09-11, release date: 2013-04-17, Last modification date: 2023-11-08)

Primary citation

Ishii, S.,Yano, T.,Okamoto, A.,Murakawa, T.,Hayashi, H.
Boundary of the Nucleotide-Binding Domain of Streptococcus ComA Based on Functional and Structural Analysis
Biochemistry, 52:2545-2555, 2013

PubMed Abstract: The ATP-binding cassette (ABC) transporter ComA is a key molecule essential for the first step of the quorum-sensing system of Streptococcus. The nucleotide binding domains (NBD) of Streptococcus mutans ComA with different N termini, NBD1 (amino acid residues 495-760), NBD2 (517-760), and NBD3 (528-760), were expressed, purified, and characterized. The shortest NBD3 corresponds to the region commonly defined as NBD in the database searches of ABC transporters. A kinetic analysis showed that the extra N-terminal region conferred a significantly higher ATP hydrolytic activity on the NBD at a neutral pH. Gel-filtration, X-ray crystallography, and mutational analyses suggest that at least four to five residues beyond the N-terminal boundary of NBD3 indeed participate in stabilizing the protein scaffold of the domain structure, thereby facilitating the ATP-dependent dimerization of NBD which is a prerequisite to the catalysis. These findings, together with the presence of a highly conserved glycine residue in this region, support the redefinition of the N-terminal boundary of the NBD of these types of ABC exporters.

PubMed: 23534432
DOI: 10.1021/bi3017069

Experimental method

X-RAY DIFFRACTION (2.69 Å)