2MLK: Three-dimensional structure of the C-terminal DNA-binding domain of RstA protein from Klebsiella pneumoniae

The RstA/RstB system is a bacterial two-component regulatory system consisting of the membrane sensor, RstB and its cognate response regulator (RR) RstA. The RstA of Klebsiella pneumoniae (kpRstA) consists of an N-terminal receiver domain (RD, residues 1-119) and a C-terminal DNA-binding domain (DBD, residues 130-236). Phosphorylation of kpRstA induces dimerization, which allows two kpRstA DBDs to bind to a tandem repeat, called the RstA box, and regulate the expression of downstream genes. Here we report the solution and crystal structures of the free kpRstA RD, DBD and DBD/RstA box DNA complex. The structure of the kpRstA DBD/RstA box complex suggests that the two protomers interact with the RstA box in an asymmetric fashion. Equilibrium binding studies further reveal that the two protomers within the kpRstA dimer bind to the RstA box in a sequential manner. Taken together, our results suggest a binding model where dimerization of the kpRstA RDs provides the platform to allow the first kpRstA DBD protomer to anchor protein-DNA interaction, whereas the second protomer plays a key role in ensuring correct recognition of the RstA box.
PDB ID: 2MLKDownload
MMDB ID: 121419
PDB Deposition Date: 2014/3/2
Updated in MMDB: 2014/08
Experimental Method:
solution nmr
Source Organism:
Similar Structures:
Biological Unit for 2MLK: monomeric; determined by author
Molecular Components in 2MLK
Label Count Molecule
Protein (1 molecule)
Molecule annotation
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