PDBsum entry 1x9x

Transferase

PDB id: 1x9x

Contents

Protein chains

62 a.a. *

* Residue conservation analysis

PDB id:

1x9x

Name:

Transferase

Title:

Solution structure of dimeric sam domain from mapkkk ste11

Structure:

Serine/threonine-protein kinase ste11. Chain: a, b. Fragment: sam domain (residues 37-104). Engineered: yes

Source:

Saccharomyces cerevisiae. Baker's yeast. Organism_taxid: 4932. Gene: ste11. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

NMR struc:

8 models

Authors:

S.Bhattacharjya,P.Xu,R.Gingras,R.Shaykhutdinov,C.Wu,M.Whiteway,F.Ni

Key ref:

S.Bhattacharjya et al. (2004). Solution structure of the dimeric SAM domain of MAPKKK Ste11 and its interactions with the adaptor protein Ste50 from the budding yeast: implications for Ste11 activation and signal transmission through the Ste50-Ste11 complex. J Mol Biol, 344, 1071-1087. PubMed id: 15544813 DOI: 10.1016/j.jmb.2004.09.018

Date:

24-Aug-04 Release date: 30-Aug-05

Protein chains

P23561  (STE11_YEAST) -  Serine/threonine-protein kinase STE11 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 717 a.a.

Struc: 62 a.a.

Enzyme reactions

• Enzyme class: E.C.2.7.11.25 - mitogen-activated protein kinase kinase kinase.
• Reaction:
  1. L-seryl-[protein] + ATP = O-phospho-L-seryl-[protein] + ADP + H⁺
  2. L-threonyl-[protein] + ATP = O-phospho-L-threonyl-[protein] + ADP + H⁺

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1016/j.jmb.2004.09.018

J Mol Biol 344:1071-1087 (2004)

PubMed id: 15544813

Solution structure of the dimeric SAM domain of MAPKKK Ste11 and its interactions with the adaptor protein Ste50 from the budding yeast: implications for Ste11 activation and signal transmission through the Ste50-Ste11 complex.

S.Bhattacharjya, P.Xu, R.Gingras, R.Shaykhutdinov, C.Wu, M.Whiteway, F.Ni.

ABSTRACT

Ste11, a homologue of mammalian MAPKKKs, together with its binding partner Ste50 works in a number of MAPK signaling pathways of Saccharomyces cerevisiae. Ste11/Ste50 binding is mediated by their sterile alpha motifs or SAM domains, of which homologues are also found in many other intracellular signaling and regulatory proteins. Here, we present the solution structure of the SAM domain or residues D37-R104 of Ste11 and its interactions with the cognate SAM domain-containing region of Ste50, residues M27-Q131. NMR pulse-field-gradient (PFG) and rotational correlation time measurements (tauc) establish that the Ste11 SAM domain exists predominantly as a symmetric dimer in solution. The solution structure of the dimeric Ste11 SAM domain consists of five well-defined helices per monomer packed into a compact globular structure. The dimeric structure of the SAM domain is maintained by a novel dimer interface involving interactions between a number of hydrophobic residues situated on helix 4 and at the beginning of the C-terminal long helix (helix 5). The dimer structure may also be stabilized by potential salt bridge interactions across the interface. NMR H/2H exchange experiments showed that binding of the Ste50 SAM to the Ste11 SAM very likely involves the positively charged extreme C-terminal region as well as exposed hydrophobic patches of the dimeric Ste11 SAM domain. The dimeric structure of the Ste11 SAM and its interactions with the Ste50 SAM may have important roles in the regulation and activation of the Ste11 kinase and signal transmission and amplifications through the Ste50-Ste11 complex.

Selected figure(s)

Figure 2.
Figure 2. 15N NMR relaxation data of the 15N-labeled Ste11 SAM domain in the dimeric state. (a) 15N longitudinal relaxation rates (R[1]=1/T[1]); (b) 15N transverse relaxation rates (R[2]=1/T[2]); and (c) heteronuclear Overhauser effects (HNOE) between proton and the 15N nuclei of the amide 15NH group.

Figure 6.
Figure 6. Space-filling representation of the hydrophobic core (a) and a stick diagram of salt-bridges (b) at the dimeric interface of the Ste11 SAM domain. The helices are represented by ribbons. (c) Stick diagram of the dimeric structure of the Ste11 SAM domain showing surface-exposed hydrophobic residues. (d) Electrostatic potential surface of the Ste11 SAM dimer. The asymmetric charge distribution of the dimer of each face is shown. Colored in red is negatively charged, blue positively charged and white neutral. This Figure was made with the GRASP program.54

The above figures are reprinted by permission from Elsevier: J Mol Biol (2004, 344, 1071-1087) copyright 2004.

Figures were selected by an automated process.