Structure determination and prediction: A study on human Tom20

In order to study the structural and functional properties of hTom20 variou s truncations of the cytosolic domain were expressed. CD spectroscopy was a pplied to determine structural features of these constructs. Our findings s uggest that the N-terminal part (aa30-60) of the cytosolic domain contains an a-helical region which functions as bridge between membrane binding doma in (aa30-49) and N-terminal targeting signal binding domain (aa50-89). The last five amino acids of the protein do not contain secondary structure ele ments, but influence the binding behavior to N-terminal targeting signal bi nding domain-containing proteins, An interaction between the C-terminus and the N-terminal located region is proposed. Structural features of the cyto solic domain of human Tom20 are discussed using a model derived from second ary structure prediction and fold recognition. (C) 1999 Elsevier Science B. V. All rights reserved.