PDBsum entry 2i3s

Cell cycle

PDB id: 2i3s

Contents

Protein chains

334 a.a. *

36 a.a. *

Waters ×644

* Residue conservation analysis

PDB id:

2i3s

Name:

Cell cycle

Title:

Bub3 complex with bub1 glebs motif

Structure:

Cell cycle arrest protein. Chain: a, c, e. Engineered: yes. Checkpoint serine/threonine-protein kinase. Chain: b, d, f. Synonym: bub1 glebs motif. Engineered: yes

Source:

Saccharomyces cerevisiae. Baker's yeast. Organism_taxid: 4932. Gene: bub3, yor026w, or26.16. Expressed in: escherichia coli. Expression_system_taxid: 562. Synthetic: yes. Other_details: chemically synthesized peptide.

Resolution:

1.90Å R-factor: 0.219 R-free: 0.262

Authors:

N.A.Larsen,S.C.Harrison

Key ref:

N.A.Larsen et al. (2007). Structural analysis of Bub3 interactions in the mitotic spindle checkpoint. Proc Natl Acad Sci U S A, 104, 1201-1206. PubMed id: 17227844 DOI: 10.1073/pnas.0610358104

Date:

20-Aug-06 Release date: 09-Jan-07

Protein chains

P26449  (BUB3_YEAST) -  Cell cycle arrest protein BUB3 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 341 a.a.

Struc: 334 a.a.

Protein chains

P41695  (BUB1_YEAST) -  Checkpoint serine/threonine-protein kinase BUB1 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 1021 a.a.

Struc: 36 a.a.

Enzyme reactions

• Enzyme class: Chains B, D, F: E.C.2.7.11.1 - non-specific serine/threonine protein 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: 10.1073/pnas.0610358104

Proc Natl Acad Sci U S A 104:1201-1206 (2007)

PubMed id: 17227844

Structural analysis of Bub3 interactions in the mitotic spindle checkpoint.

N.A.Larsen, J.Al-Bassam, R.R.Wei, S.C.Harrison.

ABSTRACT

The Mad3/BubR1, Mad2, Bub1, and Bub3 proteins are gatekeepers for the transition from metaphase to anaphase. Mad3 from Saccharomyces cerevisiae has homology to Bub1 but lacks a corresponding C-terminal kinase domain. Mad3 forms a stable heterodimer with Bub3. Negative-stain electron microscopy shows that Mad3 is an extended molecule (approximately 200 A long), whereas Bub3 is globular. The Gle2-binding-sequence (GLEBS) motifs found in Mad3 and Bub1 are necessary and sufficient for interaction with Bub3. The calorimetrically determined dissociation constants for GLEBS-motif peptides and Bub3 are approximately 5 microM. Crystal structures of these peptides with Bub3 show that the interactions for Mad3 and Bub1 are similar and mutually exclusive. In both structures, the GLEBS peptide snakes along the top surface of the beta-propeller, forming an extensive interface. Mutations in either protein that disrupt the interface cause checkpoint deficiency and chromosome instability. We propose that the structure imposed on the GLEBS segment by its association with Bub3 enables recruitment to unattached kinetochores.

Selected figure(s)

Figure 2.
Fig. 2. Negative-stain electron microscopy. Shown are wide fields with higher magnification insets. (A) Bub3 appears as isolated punctate objects. (B) Mad3 resembles elongated beads on a string.

Figure 5.
Fig. 5. Mad3 and R197E Bub3 do not associate. (A) Mad3 was mixed with excess Bub3 mutant and analyzed by gel filtration. (B) Coomassie-stained gel of peak fractions from A showing that the Bub3 mutant does not coelute with Mad3.

Figures were selected by an automated process.