NMR structure and mutagenesis of the N-terminal Dbl homology domain of the nucleotide exchange factor Trio.
Guanine nucleotide exchange factors for the Rho family of GTPases contain a Dbl homology (DH) domain responsible for catalysis and a pleckstrin homology (PH) domain whose function is unknown. Here we describe the solution structure of the N-terminal DH domain of Trio that catalyzes nucleotide exchange for Rac1. The all-alpha-helical protein has a very different structure compared to other exchange factors. Based on site-directed mutagenesis, functionally important residues of the DH domain were identified. They are all highly conserved and reside in close proximity on two a helices. In addition, we have discovered a unique capability of the PH domain to enhance nucleotide exchange in DH domain-containing proteins.
Liu
X
X
Pharmaceutical Discovery Division, Abbott Laboratories, Abbott Park, Illinois 60064, USA.
Wang
H
H
Eberstadt
M
M
Schnuchel
A
A
Olejniczak
E T
ET
Meadows
R P
RP
Schkeryantz
J M
JM
Janowick
D A
DA
Harlan
J E
JE
Harris
E A
EA
Staunton
D E
DE
Fesik
S W
SW
D001798:Blood Proteins / Q000737:chemistry / Q000235:genetics; D020662:Guanine Nucleotide Exchange Factors; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009711:Nucleotides / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
D001798:Blood Proteins; D020662:Guanine Nucleotide Exchange Factors; D009711:Nucleotides; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; C039077:platelet protein P47; D017346:Protein Serine-Threonine Kinases; C099628:TRIO protein, human