3K6V

M. acetivorans Molybdate-Binding Protein (ModA) in Citrate-Bound Open Form

Summary for 3K6V

• Entry DOI: 10.2210/pdb3k6v/pdb
• Related: 3K6U 3K6W 3K6X
• Descriptor: Solute-binding protein MA_0280, CITRIC ACID (3 entities in total)
• Functional Keywords: moda, molybdate, methanosarcina acetivorans, periplasmic binding protein, abc transporter, transport protein, ligand, metal-binding protein
• Biological source: Methanosarcina acetivorans
• Total number of polymer chains: 1
• Total formula weight: 39352.28

Authors

Chan, S.,Giuroiu, I.,Chernishof, I.,Sawaya, M.R.,Chiang, J.,Gunsalus, R.P.,Arbing, M.A.,Perry, L.J. (deposition date: 2009-10-09, release date: 2010-01-12, Last modification date: 2024-02-21)

Primary citation

Chan, S.,Giuroiu, I.,Chernishof, I.,Sawaya, M.R.,Chiang, J.,Gunsalus, R.P.,Arbing, M.A.,Perry, L.J.
Apo and ligand-bound structures of ModA from the archaeon Methanosarcina acetivorans
Acta Crystallogr.,Sect.F, 66:242-250, 2010

PubMed Abstract: The trace-element oxyanion molybdate, which is required for the growth of many bacterial and archaeal species, is transported into the cell by an ATP-binding cassette (ABC) transporter superfamily uptake system called ModABC. ModABC consists of the ModA periplasmic solute-binding protein, the integral membrane-transport protein ModB and the ATP-binding and hydrolysis cassette protein ModC. In this study, X-ray crystal structures of ModA from the archaeon Methanosarcina acetivorans (MaModA) have been determined in the apoprotein conformation at 1.95 and 1.69 A resolution and in the molybdate-bound conformation at 2.25 and 2.45 A resolution. The overall domain structure of MaModA is similar to other ModA proteins in that it has a bilobal structure in which two mixed alpha/beta domains are linked by a hinge region. The apo MaModA is the first unliganded archaeal ModA structure to be determined: it exhibits a deep cleft between the two domains and confirms that upon binding ligand one domain is rotated towards the other by a hinge-bending motion, which is consistent with the 'Venus flytrap' model seen for bacterial-type periplasmic binding proteins. In contrast to the bacterial ModA structures, which have tetrahedral coordination of their metal substrates, molybdate-bound MaModA employs octahedral coordination of its substrate like other archaeal ModA proteins.

PubMed: 20208152
DOI: 10.1107/S1744309109055158

Experimental method

X-RAY DIFFRACTION (1.69 Å)