Biochemical evidence for multiple dimeric states of the Sinorhizobium meliloti DctD receiver domain.
X-ray crystal structures suggest very different dimeric states for the inactive and active forms of the two-component receiver domain of Sinorhizobium meliloti DctD, a sigma(54)-dependent AAA+ ATPase. Moreover, the receiver domain in crystals grown from unphosphorylated protein is refractory to phosphorylation whereas solution protein is fully phosphorylatable, and equilibrium analytical ultracentrifugation data are consistent with solution dimers for both phosphorylated and unphosphorylated forms of the protein. Here we report biochemical data consistent with the presence of multiple dimeric conformations in the inactive and active states, and evidence for significant change in the dimeric state upon activation by phosphorylation or binding of Mg(2+) and BeF(3)(-).
Department of Biochemistry and Molecular Biology and Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Sungdae
S
Park
Hong
H
Zhang
A Daniel
AD
Jones
B Tracy
BT
Nixon
D001426:Bacterial Proteins / Q000737:chemistry*; D025243:Bacterial Proton-Translocating ATPases / Q000737:chemistry; D002942:Circular Dichroism; D018360:Crystallography, X-Ray; D019281:Dimerization; D019906:Nuclear Magnetic Resonance, Biomolecular; D010446:Peptide Fragments / Q000737:chemistry*; D010766:Phosphorylation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016962:Sinorhizobium meliloti / Q000737:chemistry*; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000737:chemistry*; D014461:Ultracentrifugation
D001426:Bacterial Proteins; D010446:Peptide Fragments; D012996:Solutions; D014157:Transcription Factors; C073788:dctD protein, Rhizobium meliloti; D025243:Bacterial Proton-Translocating ATPases