Receiver domain of sensor histidine kinase CKI1: Difference between revisions
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==Structure and effects of magnesium binding in the active site== | ==Structure and effects of magnesium binding in the active site== | ||
[[Image:Cki1signalizace.png|250px|left|thumb| CKI1 acts as constitutively active histidine-kinaze in MSP signaling in ''Arabidopsis''.]]]] | |||
The crystal structure of CKI1RD shows the conformational conservation of RDs belonging to CheY-like protein superfamily (Stock et al., 1989, Wilson, 2009). CKI1RD is folded in a (alpha/beta)5 manner with central beta-sheet formed from parallel beta-strands (beta2-1-3-4-5) surrounded on both sides by two (alpha 1 and5) and three (al-pha2,3,4) alpha helices. Secondary structure elements are connected by five loops L1-L5 on the face side of the protein. The active site with phosphoacceptor D1050 is located at the C-termini of the central beta3-strand in a pocket delineated loops L1, L3 and L5. A highly conserved triad of carboxyl oxygens formed by D1050 together with D992 and D993 and carbonyl oxygen of Q1052 give the active site an acidic character. This architecture of the active site is well conserved among CheY-like superfamily and corresponds to the phosphotransfer function of the receiver domains. | The crystal structure of CKI1RD shows the conformational conservation of RDs belonging to CheY-like protein superfamily (Stock et al., 1989, Wilson, 2009). CKI1RD is folded in a (alpha/beta)5 manner with central beta-sheet formed from parallel beta-strands (beta2-1-3-4-5) surrounded on both sides by two (alpha 1 and5) and three (al-pha2,3,4) alpha helices. Secondary structure elements are connected by five loops L1-L5 on the face side of the protein. The active site with phosphoacceptor D1050 is located at the C-termini of the central beta3-strand in a pocket delineated loops L1, L3 and L5. A highly conserved triad of carboxyl oxygens formed by D1050 together with D992 and D993 and carbonyl oxygen of Q1052 give the active site an acidic character. This architecture of the active site is well conserved among CheY-like superfamily and corresponds to the phosphotransfer function of the receiver domains. | ||