tailieunhanh - Báo cáo khoa học: The capsid protein of human immunodeficiency virus: intersubunit interactions during virus assembly

The capsid protein (CA) of HIV-1 is composed of two domains, the N-ter-minal domain (NTD) and the C-terminal domain (CTD). During the assembly of the immature HIV-1 particle, both CA domains constitute a part of the Gag polyprotein, which forms a spherical capsid comprising up to 5000 radially arranged, extended subunits. | MINIREVIEW The capsid protein of human immunodeficiency virus intersubunit interactions during virus assembly Mauricio G. Mateu Centro de Biologia Molecular Severo Ochoa CSIC-UAM Universidad Autonoma de Madrid Spain Keywords capsid conformationalstability and dynamics human immunodeficiency virus molecular recognition protein association protein conformation protein structure- function relationships virus assembly Correspondence M. G. Mateu Centro de Biologia Molecular Severo Ochoa Universidad Autonoma de Madrid Cantoblanco 28049 Madrid Spain Fax 34 91 1964420 Tel 34 91 1964575 E-mail mgarcia@ Website http webs CBMSO IdObjeto 19 ChangeLanguage 2 Received 23 February 2009 revised 12 August 2009 accepted 20 August 2009 doi The capsid protein CA of HIV-1 is composed of two domains the N-ter-minal domain NTD and the C-terminal domain CTD . During the assembly of the immature HIV-1 particle both CA domains constitute a part of the Gag polyprotein which forms a spherical capsid comprising up to 5000 radially arranged extended subunits. Gag-Gag interactions in the immature capsid are mediated in large part by interactions between CA domains which are involved in the formation of a lattice of connected Gag hexamers. After Gag proteolysis during virus maturation the CA protein is released and approximately 1000-1500 free CA subunits self-assemble into a truncated cone-shaped capsid. In the mature capsid NTD-NTD and NTD-CTD interfaces are involved in the formation of CA hexamers and CTD-CTD interfaces connect neighboring hexamers through homodimerization. The CA-CA interfaces involved in the assembly of the immature capsid and those forming the mature capsid are different at least in part. CA appears to have evolved an extraordinary conformational plasticity which allows the creation of multiple CA-CA interfaces and the occurrence of CA conformational switches. This .