PDBsum entry: 2c2a

Transferase

PDB id: 2c2a

Contents

Protein chain

241 a.a. *

Ligands

ADP

SO4

Waters ×179

* Residue conservation analysis

PDB id:

2c2a

Name:

Transferase

Title:

Structure of the entire cytoplasmic portion of a sensor histidine kinase protein

Structure:

Sensor histidine kinase. Chain: a. Fragment: cytoplasmic portion residues 233-489. Synonym: histidine kinase tm0853. Engineered: yes

Source:

Thermotoga maritima. Organism_taxid: 2336. Expressed in: escherichia coli. Expression_system_taxid: 562.

Biol. unit:

Dimer (from PDB file)

Resolution:

1.9Å R-factor: 0.246 R-free: 0.275

Authors:

A.Marina,C.D.Waldburger,W.A.Hendrickson

Key ref:

A.Marina et al. (2005). Structure of the entire cytoplasmic portion of a sensor histidine-kinase protein. EMBO J, 24, 4247-4259. PubMed id: 16319927 DOI: 10.1038/sj.emboj.7600886

Date:

27-Sep-05 Release date: 21-Nov-05

Protein chain

Q9WZV7  (Q9WZV7_THEMA) -  Sensor histidine kinase

Seq: 489 a.a.

Struc: 241 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

 Gene Ontology (GO) functional annotation 

• Cellular component: membrane (1 term)
• Biological process: signal transduction (3 terms)
• Biochemical function: signal transducer activity (5 terms)

DOI no: 10.1038/sj.emboj.7600886

EMBO J 24:4247-4259 (2005)

PubMed id: 16319927

Structure of the entire cytoplasmic portion of a sensor histidine-kinase protein.

A.Marina, C.D.Waldburger, W.A.Hendrickson.

ABSTRACT

The large majority of histidine kinases (HKs) are multifunctional enzymes having autokinase, phosphotransfer and phosphatase activities, and most of these are transmembrane sensor proteins. Sensor HKs possess conserved cytoplasmic phosphorylation and ATP-binding kinase domains. The different enzymatic activities require participation by one or both of these domains, implying the need for different conformational states. The catalytic domains are linked to the membrane through a coiled-coil segment that sometimes includes other domains. We describe here the first crystal structure of the complete cytoplasmic region of a sensor HK, one from the thermophile Thermotoga maritima in complex with ADPbetaN at 1.9 A resolution. The structure reveals previously unidentified functions for several conserved residues and reveals the relative disposition of domains in a state seemingly poised for phosphotransfer. The structure thereby inspires hypotheses for the mechanisms of autophosphorylation, phosphotransfer and response-regulator dephosphorylation, and for signal transduction through the coiled-coil segment. Mutational tests support the functional relevance of interdomain contacts.

Selected figure(s)

Figure 6.
Figure 6 Interactions between DHp and CA domains. Stereoview of the structural elements involved in interdomain contacts and sulfate ion interactions. The DHp domain, CA domain and interdomain-connecting loop are represented in blue, gold and green ribbon diagrams, respectively. Additionally, the 1' helix, which presents His260' as a sulfate ligand, is shown in gray. The interacting side chains are shown as sticks with the same carbon atom color as the corresponding domain, except the sulfate-interacting residues that are in gray. Nitrogen, oxygen, sulfur and nucleotide molecule are drawn in blue, red, black and magenta, respectively. Residue labels take the colors of their domains. Hydrogen bonds and salt bridges between the sulfate ion and interacting residues are indicated by purple dots.

Figure 8.
Figure 8 Structure-based schematic of the reactions catalyzed by HK sensors. The kinase autophosphorylation (A arrow B), phosphotransferase (B arrow A^*) and phosphatase (A^* arrow A) activities are shown on projected outlines of the enzyme and protein-substrate models. Positions of N and C termini, ATP and the phospho-accepting histidine (H) are indicated on an HK dimer (orange and green). Position of phospho-accepting aspartate (D) is indicated on a RR (red). The transferred phosphoryl group is indicated as a yellow asterisk.

The above figures are reprinted by permission from Macmillan Publishers Ltd: EMBO J (2005, 24, 4247-4259) copyright 2005.

Figures were selected by an automated process.