title: Structural and functional insight into ADF/cofilin from Trypanosoma brucei.
abstract: The ADF/cofilin family has been characterized as a group of actin-binding proteins critical for controlling the assembly of actin within the cells. In this study, the solution structure of the ADF/cofilin from Trypanosoma brucei (TbCof) was determined by NMR spectroscopy. TbCof adopts the conserved ADF/cofilin fold with a central β-sheet composed of six β-strands surrounded by five α-helices. Isothermal titration calorimetry experiments denoted a submicromolar affinity between TbCof and G-actin, and the affinity between TbCof and ADP-G-actin was five times higher than that between TbCof and ATP-G-actin at low ionic strength. The results obtained from electron microscopy and actin filament sedimentation assays showed that TbCof depolymerized but did not co-sediment with actin filaments and its ability of F-actin depolymerization was pH independent. Similar to actin, TbCof was distributed throughout the cytoplasm. All our data indicate a structurally and functionally conserved ADF/cofilin from Trypanosoma brucei.
authors: Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, P R China.
authors: Kun
authors: K
authors: Dai
authors: Shanhui
authors: S
authors: Liao
authors: Jiahai
authors: J
authors: Zhang
authors: Xuecheng
authors: X
authors: Zhang
authors: Xiaoming
authors: X
authors: Tu
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D051339:Actin Depolymerizing Factors / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D000199:Actins / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D000595:Amino Acid Sequence; D002151:Calorimetry; D009682:Magnetic Resonance Spectroscopy; D062105:Molecular Docking Simulation; D008969:Molecular Sequence Data; D058105:Polymerization; D011485:Protein Binding; D021381:Protein Transport; D015800:Protozoan Proteins / Q000737:chemistry* / Q000378:metabolism*; D016415:Sequence Alignment; D012996:Solutions; D040681:Structural Homology, Protein; D013329:Structure-Activity Relationship; D014346:Trypanosoma brucei brucei / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D051339:Actin Depolymerizing Factors; D000199:Actins; D015800:Protozoan Proteins; D012996:Solutions