PDBsum entry 4q7k

Metal binding protein

PDB id: 4q7k

Contents

Protein chain

188 a.a.

Waters ×61

PDB id:

4q7k

Name:

Metal binding protein

Title:

Structure of nbd287 of tm287/288

Structure:

Abc transporter. Chain: a. Fragment: unp residues 330-577. Synonym: abc transporter, atp-binding protein, lipid a export atp- binding/permease protein msba. Engineered: yes

Source:

Thermotoga maritima. Organism_taxid: 243274. Strain: atcc 43589 / msb8 / dsm 3109 / jcm 10099. Gene: tm_0287, thema_03290, tmari_0285. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

1.80Å R-factor: 0.205 R-free: 0.212

Authors:

M.A.Bukowska,M.Hohl,M.G.Gruetter,M.A.Seeger

Key ref:

M.A.Bukowska et al. (2015). A Transporter Motor Taken Apart: Flexibility in the Nucleotide Binding Domains of a Heterodimeric ABC Exporter. Biochemistry, 54, 3086-3099. PubMed id: 25947941 DOI: 10.1021/acs.biochem.5b00188

Date:

25-Apr-14 Release date: 20-May-15

Protein chain

Q9WYC3  (Q9WYC3_THEMA) -  ABC transporter, ATP-binding protein from Thermotoga maritima (strain ATCC 43589 / DSM 3109 / JCM 10099 / NBRC 100826 / MSB8)

Seq: 577 a.a.

Struc: 188 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1021/acs.biochem.5b00188

Biochemistry 54:3086-3099 (2015)

PubMed id: 25947941

A Transporter Motor Taken Apart: Flexibility in the Nucleotide Binding Domains of a Heterodimeric ABC Exporter.

M.A.Bukowska, M.Hohl, E.R.Geertsma, L.M.Hürlimann, M.G.Grütter, M.A.Seeger.

ABSTRACT

ABC exporters are ubiquitous multidomain transport proteins that couple ATP hydrolysis at a pair of nucleotide binding domains to substrate transport across the lipid bilayer mediated by two transmembrane domains. Recently, the crystal structure of the heterodimeric ABC exporter TM287/288 was determined. One of its asymmetric ATP binding sites is called the degenerate site; it binds nucleotides tightly but is impaired in terms of ATP hydrolysis. Here we report the crystal structures of both isolated motor domains of TM287/288. Unexpectedly, structural elements constituting the degenerate ATP binding site are disordered in these crystals and become structured only in the context of the full-length transporter. In addition, hydrogen bonding patterns of key residues, including those of the catalytically important Walker B and the switch loop motifs, are fundamentally different in the solitary NBDs compared to those in the intact transport protein. The structures reveal crucial interdomain contacts that need to be established for the proper assembly of the functional transporter complex.