The solution structure of the S.cerevisiae Ste11 MAPKKK SAM domain and its partnership with Ste50

Ste11 is a MAPKKK from Saccharomyces cerevisiae that helps mediate the response to mating pheromone and the ability to thrive in high-salt environments. These diverse functions are facilitated by a direct interaction between the SAM domain of Ste11 with the SAM domain of its regulatory partner, Ste5...

Full description

Saved in:
Bibliographic Details
Published in:Journal of molecular biology 2004-09, Vol.342 (2), p.681-693
Main Authors: Kwan, Jamie J, Warner, Neil, Pawson, Tony, Donaldson, Logan W
Format: Article
Language:English
Subjects:
Amino Acid Sequence
Dimerization
MAP Kinase Kinase Kinases - chemistry
MAP Kinase Kinase Kinases - genetics
MAP Kinase Kinase Kinases - metabolism
Molecular Sequence Data
Mutation
Protein Structure, Tertiary
Saccharomyces cerevisiae
Saccharomyces cerevisiae - enzymology
Saccharomyces cerevisiae - metabolism
Saccharomyces cerevisiae Proteins - metabolism
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Ste11 is a MAPKKK from Saccharomyces cerevisiae that helps mediate the response to mating pheromone and the ability to thrive in high-salt environments. These diverse functions are facilitated by a direct interaction between the SAM domain of Ste11 with the SAM domain of its regulatory partner, Ste50. We have solved the NMR structure of the Ste11 SAM domain (PDB 1OW5), which reveals a compact, five alpha-helix bundle and a high degree of structural similarity to the Polyhomeotic SAM domain. The combined study of Ste11 SAM rotational correlation times and crosslinking to Ste50-SAM has suggested a mode through which Ste11-SAM oligomerizes and selectively associates with Ste50-SAM. To probe homotypic and heterotypic interations, Ste11-SAM variants each containing a substitution of a surface-exposed hydrophobic residue were constructed. An I59R variant of Ste11-SAM, disrupted binding to Ste50-SAM in vitro. Yeast expressing full-length Ste11-I59R could neither respond to mating pheromone nor thrive in high salt media-demonstrating that the interaction between Ste11 and Ste50 SAM domains is a prerequisite for key signal transduction events.
ISSN:0022-2836
DOI:10.1016/j.jmb.2004.06.064