Docking analysis of PknQ with MupFHA domain.

Abstract

<p>(<b>A</b>) Homology modeling derived structural models showing docking of wild-type PknQ (stick diagram) with the wild-type FHA domain variable loop region of MupFHA (green ribbon diagram). Phosphate group (orange) has been added to Ser¹⁷⁰ and Thr¹⁷⁴ of PknQ and the phosphorylated residues have been renamed as Sep170 and Tpo174, respectively. The red encircled region of interaction has been enlarged in (<b>B</b>). The residues Arg⁴¹, Arg⁵³, Ser⁵⁵, Arg⁵⁶ and Ser⁷⁵ of MupFHA show stable interactions with the PknQ activation loop and form H-bonds with the negatively charged pSer¹⁷⁰ (Sep170) and pThr¹⁷⁴ (Tpo174). (<b>C</b>) Enlarged region of interaction between PknQ-pThr¹⁷⁴ and MupFHA. Canonical interaction of pThr¹⁷⁴ is observed showing H-bonds with Arg⁵³, Ser⁵⁵ and Ser⁷⁵ of MupFHA (see text). (<b>D</b>) Enlarged region of interaction between PknQ-pSer¹⁷⁰ and MupFHA. PknQ-pSer¹⁷⁰ is shown to be anchored by the residues Arg⁴¹ and Arg⁵⁶ of MupFHA. (<b>E</b>) Region of interaction between PknQ-pThr¹⁷⁴ and MupFHA^S55A (in red stick). (<b>F</b>) Region of interaction between PknQ-pSer¹⁷⁰ and MupFHA^R41A (in red stick). Both (E) and (F) show the loss of H-bond network and thus destabilized interaction between PknQ and MupFHA.</p