Structure and mutational analysis of Rab GDP-dissociation inhibitor.
The crystal structure of the bovine alpha-isoform of Rab GDP-dissociation inhibitor (GDI), which functions in vesicle-membrane transport to recycle and regulate Rab GTPases, has been determined to a resolution of 1.81 A. GDI is constructed of two main structural units, a large complex multisheet domain I and a smaller alpha-helical domain II. The structural organization of domain I is surprisingly closely related to FAD-containing monooxygenases and oxidases. Sequence-conserved regions common to GDI and the choroideraemia gene product, which delivers Rab to catalytic subunits of Rab geranylgeranyltransferase II, are clustered on one face of the molecule. The two most sequence-conserved regions, which form a compact structure at the apex of GDI, are shown by site-directed mutagenesis to play a critical role in the binding of Rab proteins.
Schalk
I
I
Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
Zeng
K
K
Wu
S K
SK
Stura
E A
EA
Matteson
J
J
Huang
M
M
Tandon
A
A
Wilson
I A
IA
Balch
W E
WE
D048868:Adaptor Proteins, Signal Transducing; D019883:Alkyl and Aryl Transferases; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry; D002417:Cattle; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D019204:GTP-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020730:Guanine Nucleotide Dissociation Inhibitors; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D016415:Sequence Alignment; D013329:Structure-Activity Relationship; D020691:rab GTP-Binding Proteins; D020692:rab3 GTP-Binding Proteins
D048868:Adaptor Proteins, Signal Transducing; C081787:CHM protein, human; D002352:Carrier Proteins; C086796:GDP dissociation inhibitor 1; D020730:Guanine Nucleotide Dissociation Inhibitors; D019883:Alkyl and Aryl Transferases; D019204:GTP-Binding Proteins; D020691:rab GTP-Binding Proteins; D020692:rab3 GTP-Binding Proteins