The transmembrane homotrimer of ADAM 1 in model lipid bilayers.
Protein Sci
; 16(2): 285-92, 2007 Feb.
Article
en En
| MEDLINE
| ID: mdl-17189481
Fertilin is a transmembrane protein heterodimer formed by the two subunits fertilin alpha and fertilin beta that plays an important role in sperm-egg fusion. Fertilin alpha and beta are members of the ADAM family, and contain each one transmembrane alpha-helix, and are termed ADAM 1 and ADAM 2, respectively. ADAM 1 is the subunit that contains a putative fusion peptide, and we have explored the possibility that the transmembrane alpha-helical domain of ADAM 1 forms homotrimers, in common with other viral fusion proteins. Although this peptide was found to form various homooligomers in SDS, the infrared dichroic data obtained with the isotopically labeled peptide at specific positions is consistent with the presence of only one species in DMPC or POPC lipid bilayers. Comparison of the experimental orientational data with molecular dynamics simulations performed with sequence homologues of ADAM 1 show that the species present in lipid bilayers is only consistent with an evolutionarily conserved homotrimeric model for which we provide a backbone structure. These results support a model where ADAM 1 forms homotrimers as a step to create a fusion active intermediate.
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Proteínas ADAM
/
Membrana Dobles de Lípidos
Idioma:
En
Revista:
Protein Sci
Asunto de la revista:
BIOQUIMICA
Año:
2007
Tipo del documento:
Article