PDBsum entry 3e7e

Transferase

PDB id: 3e7e

Contents

Protein chain

333 a.a. *

Ligands

ATP

Metals

_CL ×2

_MG

Waters ×19

* Residue conservation analysis

Superseded by:

4r8q

PDB id:

3e7e

Name:

Transferase

Title:

Structure and substrate recruitment of the human spindle checkpoint kinase bub

Structure:

Mitotic checkpoint serine/threonine-protein kinase bub1. Chain: a. Fragment: unp residues 724-1085. Synonym: hbub1, bub1a. Engineered: yes

Source:

Homo sapiens. Organism_taxid: 9606. Gene: bub1, bub1l. Expressed in: spodoptera frugiperda. Expression_system_cell_line: sf9.

Resolution:

2.31Å R-factor: 0.238 R-free: 0.302

Authors:

J.Kang,M.Yang,B.Li,W.Qi,C.Zhang,K.Shokat,D.R.Tomchick,M.Machius,H.Yu

Key ref:

J.Kang et al. (2008). Structure and substrate recruitment of the human spindle checkpoint kinase Bub1. Mol Cell, 32, 394-405. PubMed id: 18995837 DOI: 10.1016/j.molcel.2008.09.017

Date:

18-Aug-08 Release date: 25-Nov-08

Protein chain

O43683  (BUB1_HUMAN) -  Mitotic checkpoint serine/threonine-protein kinase BUB1 from Homo sapiens

Seq: 1085 a.a.

Struc: 333 a.a.

Enzyme reactions

• Enzyme class: 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⁺

L-seryl-[protein] (Bound ligand (Het Group name = ATP) corresponds exactly) + ATP = O-phospho-L-seryl-[protein] + ADP + H(+)

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

reference

DOI no: 10.1016/j.molcel.2008.09.017

Mol Cell 32:394-405 (2008)

PubMed id: 18995837

Structure and substrate recruitment of the human spindle checkpoint kinase Bub1.

J.Kang, M.Yang, B.Li, W.Qi, C.Zhang, K.M.Shokat, D.R.Tomchick, M.Machius, H.Yu.

ABSTRACT

In mitosis, the spindle checkpoint detects a single unattached kinetochore, inhibits the anaphase-promoting complex or cyclosome (APC/C), and prevents premature sister chromatid separation. The checkpoint kinase Bub1 contributes to checkpoint sensitivity through phosphorylating the APC/C activator, Cdc20, and inhibiting APC/C catalytically. We report here the crystal structure of the kinase domain of Bub1, revealing the requirement of an N-terminal extension for its kinase activity. Though the activation segment of Bub1 is ordered and has structural features indicative of active kinases, the C-terminal portion of this segment sterically restricts substrate access to the active site. Bub1 uses docking motifs, so-called KEN boxes, outside its kinase domain to recruit Cdc20, one of two known KEN box receptors. The KEN boxes of Bub1 are required for the spindle checkpoint in human cells. Therefore, its unusual active-site conformation and mode of substrate recruitment suggest that Bub1 has an exquisitely tuned specificity for Cdc20.

Selected figure(s)

Figure 1.
Figure 1. Structure and Inhibitor of the Extended Kinase Domain of Bub1
(A) Domain architecture of human Bub1. TPR, tetratricopeptide repeat; GLEBS, Gle2-binding sequence; KEN, lysine-glutamate-asparagine.
(B) Ribbon drawing of the crystal structure of the extended kinase domain of Bub1. The N-terminal extension is colored yellow. The substrate-binding P+1 loop is shown in green, while the rest of the activation segment is in blue. The catalytic loop is shown in red. ATP is shown as sticks. The Mg^2+ ion is shown as a gray sphere. The N and C termini are indicated. All structure figures were generated with PyMOL (http://pymol.sourceforge.net/).
(C) The ATP-binding site of Bub1. ATP is shown as sticks. The extra pocket is indicated.
(D) The chemical structure of 2OH-BNPP1.
(E) Determination of the IC[50] values of 2OH-BNPP1 against Aurora B, p38, Bub1C, and Bub1.

Figure 2.
Figure 2. The N-Terminal Extension Activates Bub1 with a Cyclin-like Mechanism
Ribbon diagrams of Bub1C, Cdk2, and Cdk2-Cyclin A. The N and C termini are indicated. The color schemes are as described in Figure 1B except that αC is colored magenta. The ATP-binding lysine residues and the conserved glutamate residues in αC are shown as sticks. Cyclin A is shown in yellow.

The above figures are reprinted from an Open Access publication published by Cell Press: Mol Cell (2008, 32, 394-405) copyright 2008.

Figures were selected by an automated process.