Solution structure and dynamics of ADF/cofilin from Leishmania donovani

• Published in: Journal of structural biology Vol. 172; no. 3; pp. 219 - 224
• Main Authors: Pathak, Prem Prakash, Pulavarti, S.V.S.R. Krishna, Jain, Anupam, Sahasrabuddhe, Amogh Anant, Gupta, Chhitar Mal, Arora, Ashish
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-12-2010
• Subjects: Actin Depolymerizing Factors - chemistry; Actins - chemistry; ADF/cofilin; Animals; Backbone dynamics; Calorimetry; Leishmania donovani; Leishmania donovani - metabolism; Magnetic Resonance Spectroscopy; Muscle, Skeletal - metabolism; NMR; Protein structure; Protozoan Proteins - chemistry; Rabbits; NMR; ADF/cofilin; Protein structure; Leishmania donovani; Backbone dynamics
• ISSN: 1047-8477; 1095-8657
• DOI: 10.1016/j.jsb.2010.07.001

Leishmania donovani ADF/cofilin (LdCof) is a novel member of ADF/cofilin family. LdCof depolymerizes, but does not co-sediment with, rabbit muscle actin filaments. Its F-actin depolymerizing activity is pH independent. Further, it possesses weak F-actin severing activity. In order to better understand its characteristic properties, we have determined the solution NMR structure of LdCof and have analyzed protein backbone dynamics from 15N-relaxation measurements. The structure of LdCof possesses a conserved ADF/cofilin fold with a central mixed β-sheet consisting of six β-strands which is surrounded by five α-helices. LdCof structure has conserved G/F-actin binding site which includes the characteristic long kinked α-helix (α3). LdCof binds to rabbit muscle ADP–G-actin with 1:1 stoichiometry (Kd∼0.2μM). The F-actin binding site is not well formed and analysis of 15N-relaxation data shows that residues in the β4–β5 loop region and C-terminal are relatively flexible, which seems to be a determinant for the low F-actin severing activity of LdCof.