TY - JOUR
T1 - Retrovirus capsid protein assembly arrangements
AU - Mayo, Keith
AU - Huseby, Doug
AU - McDermott, Jason
AU - Arvidson, Brian
AU - Finlay, Liam
AU - Barklis, Eric
N1 - Funding Information:
We are grateful for the assistance and advice from lab members, past and present, including Ayna Alfadhli, Kirk Ellison, Zac Love, Josh Seeds, and Eric Steel. We thank Stephen Fuller for the cryo-EM images of immature HIV-1 particles, and are grateful to John Briggs, Stephen Fuller, Marc Johnson, May Ma, and Volker Vogt for informative discussions of their unpublished work. This work was supported by NIGMS grants GM60170-3 and GM52914-07 (to E.B.).
PY - 2003
Y1 - 2003
N2 - During retrovirus particle assembly and morphogenesis, the retrovirus structural (Gag) proteins organize into two different arrangements: an immature form assembled by precursor Gag (PrGag) proteins; and a mature form, composed of proteins processed from PrGag. Central to both Gag protein arrangements is the capsid (CA) protein, a domain of PrGag, which is cleaved from the precursor to yield a mature Gag protein composed of an N-terminal domain (NTD), a flexible linker region, and a C-terminal domain (CTD). Because Gag interactions have proven difficult to examine in virions, a number of investigations have focused on the analysis of structures assembled in vitro. We have used electron microscope (EM) image reconstruction techniques to examine assembly products formed by two different CA variants of both human immunodeficiency virus type 1 (HIV-1) and the Moloney murine leukemia virus (M-MuLV). Interestingly, two types of hexameric protein arrangements were observed for each virus type. One organizational scheme featured hexamers composed of putative NTD dimer subunits, with sharing of subunits between neighbor hexamers. The second arrangement used apparent NTD monomers to coordinate hexamers, involved no subunit sharing, and employed putative CTD interactions to connect hexamers. Conversion between the two assembly forms may be achieved by making or breaking the proposed symmetric NTD dimer contacts in a process that appears to mimic viral morphogenesis.
AB - During retrovirus particle assembly and morphogenesis, the retrovirus structural (Gag) proteins organize into two different arrangements: an immature form assembled by precursor Gag (PrGag) proteins; and a mature form, composed of proteins processed from PrGag. Central to both Gag protein arrangements is the capsid (CA) protein, a domain of PrGag, which is cleaved from the precursor to yield a mature Gag protein composed of an N-terminal domain (NTD), a flexible linker region, and a C-terminal domain (CTD). Because Gag interactions have proven difficult to examine in virions, a number of investigations have focused on the analysis of structures assembled in vitro. We have used electron microscope (EM) image reconstruction techniques to examine assembly products formed by two different CA variants of both human immunodeficiency virus type 1 (HIV-1) and the Moloney murine leukemia virus (M-MuLV). Interestingly, two types of hexameric protein arrangements were observed for each virus type. One organizational scheme featured hexamers composed of putative NTD dimer subunits, with sharing of subunits between neighbor hexamers. The second arrangement used apparent NTD monomers to coordinate hexamers, involved no subunit sharing, and employed putative CTD interactions to connect hexamers. Conversion between the two assembly forms may be achieved by making or breaking the proposed symmetric NTD dimer contacts in a process that appears to mimic viral morphogenesis.
KW - Capsid
KW - Gag
KW - HIV
KW - Moloney murine leukemia virus
KW - Retrovirus
UR - http://www.scopus.com/inward/record.url?scp=0037258778&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037258778&partnerID=8YFLogxK
U2 - 10.1016/S0022-2836(02)01176-2
DO - 10.1016/S0022-2836(02)01176-2
M3 - Article
C2 - 12473464
AN - SCOPUS:0037258778
SN - 0022-2836
VL - 325
SP - 225
EP - 237
JO - Journal of molecular biology
JF - Journal of molecular biology
IS - 1
ER -