3CO2

Mlotik1 ion channel cyclic-nucleotide binding domain mutant

Summary for 3CO2

• Entry DOI: 10.2210/pdb3co2/pdb
• Related: 1u12 1vp6 3beh 3CL1 3CLP
• Descriptor: Mlotik1 ion channel protein (2 entities in total)
• Functional Keywords: mlotik1 cyclic-nucleotide binding domain mutant3 r307w, unliganded, membrane protein
• Biological source: Mesorhizobium loti
• Cellular location: Cell membrane; Multi-pass membrane protein: Q98GN8
• Total number of polymer chains: 4
• Total formula weight: 59472.43

Authors

Clayton, G.M.,Alteiri, S.L.,Thomas, L.R.,Morais-Cabral, J.H. (deposition date: 2008-03-27, release date: 2008-08-05, Last modification date: 2024-02-21)

Primary citation

Altieri, S.L.,Clayton, G.M.,Silverman, W.R.,Olivares, A.O.,De La Cruz, E.M.,Thomas, L.R.,Morais-Cabral, J.H.
Structural and Energetic Analysis of Activation by a Cyclic Nucleotide Binding Domain.
J.Mol.Biol., 381:655-669, 2008

PubMed Abstract: MlotiK1 is a prokaryotic homolog of cyclic-nucleotide-dependent ion channels that contains an intracellular C-terminal cyclic nucleotide binding (CNB) domain. X-ray structures of the CNB domain have been solved in the absence of ligand and bound to cAMP. Both the full-length channel and CNB domain fragment are easily expressed and purified, making MlotiK1 a useful model system for dissecting activation by ligand binding. We have used X-ray crystallography to determine three new MlotiK1 CNB domain structures: a second apo configuration, a cGMP-bound structure, and a second cAMP-bound structure. In combination, the five MlotiK1 CNB domain structures provide a unique opportunity for analyzing, within a single protein, the structural differences between the apo state and the bound state, and the structural variability within each state. With this analysis as a guide, we have probed the nucleotide selectivity and importance of specific residue side chains in ligand binding and channel activation. These data help to identify ligand-protein interactions that are important for ligand dependence in MlotiK1 and, more globally, in the class of nucleotide-dependent proteins.

PubMed: 18619611
DOI: 10.1016/j.jmb.2008.06.011

Experimental method

X-RAY DIFFRACTION (2.9 Å)