Structure-function analysis of the auxilin J-domain reveals an extended Hsc70 interaction interface.
J-domains are widespread protein interaction modules involved in recruiting and stimulating the activity of Hsp70 family chaperones. We have determined the crystal structure of the J-domain of auxilin, a protein which is involved in uncoating clathrin-coated vesicles. Comparison to the known structures of J-domains from four other proteins reveals that the auxilin J-domain is the most divergent of all J-domain structures described to date. In addition to the canonical J-domain features described previously, the auxilin J-domain contains an extra N-terminal helix and a long loop inserted between helices I and II. The latter loop extends the positively charged surface which forms the Hsc70 binding site, and is shown by directed mutagenesis and surface plasmon resonance to contain side chains important for binding to Hsc70.
Department of Biochemistry, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas 78229-3900, USA.
Jianwen
J
Jiang
Alexander B
AB
Taylor
Kondury
K
Prasad
Yumiko
Y
Ishikawa-Brush
P John
PJ
Hart
Eileen M
EM
Lafer
Rui
R
Sousa
D000595:Amino Acid Sequence; D000818:Animals; D034021:Auxilins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D002417:Cattle; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D055672:Static Electricity
D034021:Auxilins; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; C494371:HSPA8 protein, human; D010446:Peptide Fragments