PDBsum entry 3drx

Unknown function

PDB id: 3drx

Contents

Protein chains

161 a.a. *

172 a.a. *

* Residue conservation analysis

PDB id:

3drx

Name:

Unknown function

Title:

X-ray crystal structure of human kctd5 protein crystallized in high- salt buffer

Structure:

Btb/poz domain-containing protein kctd5. Chain: a, b, c, d, e. Fragment: unp residues 34-234. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: kctd5. Expressed in: escherichia coli. Expression_system_taxid: 562. Other_details: modified vector, tev protease cleavage site replacing thrombin site

Resolution:

3.11Å R-factor: 0.230 R-free: 0.275

Authors:

V.Tereshko,I.Dementieva,S.A.N.Goldstein

Key ref:

I.S.Dementieva et al. (2009). Pentameric assembly of potassium channel tetramerization domain-containing protein 5. J Mol Biol, 387, 175-191. PubMed id: 19361449 DOI: 10.1016/j.jmb.2009.01.030

Date:

11-Jul-08 Release date: 17-Feb-09

Protein chain

Q9NXV2  (KCTD5_HUMAN) -  BTB/POZ domain-containing protein KCTD5 from Homo sapiens

Seq: 234 a.a.

Struc: 161 a.a.

Protein chains

Q9NXV2  (KCTD5_HUMAN) -  BTB/POZ domain-containing protein KCTD5 from Homo sapiens

Seq: 234 a.a.

Struc: 172 a.a.

DOI no: 10.1016/j.jmb.2009.01.030

J Mol Biol 387:175-191 (2009)

PubMed id: 19361449

Pentameric assembly of potassium channel tetramerization domain-containing protein 5.

I.S.Dementieva, V.Tereshko, Z.A.McCrossan, E.Solomaha, D.Araki, C.Xu, N.Grigorieff, S.A.Goldstein.

ABSTRACT

We report the X-ray crystal structure of human potassium channel tetramerization domain-containing protein 5 (KCTD5), the first member of the family to be so characterized. Four findings were unexpected. First, the structure reveals assemblies of five subunits while tetramers were anticipated; pentameric stoichiometry is observed also in solution by scanning transmission electron microscopy mass analysis and analytical ultracentrifugation. Second, the same BTB (bric-a-brac, tramtrack, broad complex) domain surface mediates the assembly of five KCTD5 and four voltage-gated K(+) (Kv) channel subunits; four amino acid differences appear crucial. Third, KCTD5 complexes have well-defined N- and C-terminal modules separated by a flexible linker that swivels by approximately 30 degrees; the C-module shows a new fold and is required to bind Golgi reassembly stacking protein 55 with approximately 1 microM affinity, as judged by surface plasmon resonance and ultracentrifugation. Fourth, despite the homology reflected in its name, KCTD5 does not impact the operation of Kv4.2, Kv3.4, Kv2.1, or Kv1.2 channels.

Selected figure(s)

Figure 2.
Fig. 2. Structural determinants of the KCTD5 central cavity. A KCTD5 subunit in ribbon presentation showing the four segments (L1–L4) of the BTB fold and the central cavity of the pentamer assembly in cut-away. The residues that shape the central cavity are labeled in ball-and-stick mode; also shown are the solvent-accessible surfaces and cavity dimensions.

Figure 5.
Fig. 5. Intermolecular interfaces in KCTD5 assemblies. (a) Potential surfaces of individual KCTD subunit N- and C-modules. Indicated in red are acidic Asp83, Asp93, Asp95, Asp116, Glu124, Glu165–Glu167, Glu196, Asp197, Glu182, and Glu208; basic residues Arg107, Lys110, and Lys115 are indicated in blue. Gly51, Leu56, Thr57, Thr61, Leu91, Gly100, Asn114, and Gln183 are noted in gray. (b) Secondary structural elements at the interface of adjacent subunits in the N-module viewed from the center of the assembly. α-Helices and β-strands are depicted as cylinders and arrows, respectively. The L1–L4 segments of the BTB fold are shown in colors as per Fig. 2. Inset presents an expanded view of the boxed area. Residues that form interfaces are shown in ball-and-stick in yellow (subunit 1) and gray (subunit 2). H-bonds (2.6–3.4 Å) are indicated with dotted lines. Asp116 (subunit 1) and Lys115 (subunit 2) interact via main-chain atoms, and their side chains are omitted for clarity. H-bond pairs and distances are noted in further detail in Fig. S2a. (c) Secondary structural elements at the interface of adjacent subunits in the C-module viewed from the center of the assembly as in (b). Inset presents an expanded view of the boxed area as in (b). H-bond pairs and distances are noted in further detail in Fig. S2b.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2009, 387, 175-191) copyright 2009.

Figures were selected by an automated process.