PDBsum entry 2etb

Transport protein

PDB id: 2etb

Contents

Protein chain

252 a.a. *

Ligands

ACY ×4

Waters ×401

* Residue conservation analysis

PDB id:

2etb

Name:

Transport protein

Title:

Crystal structure of the ankyrin repeat domain of trpv2

Structure:

Transient receptor potential cation channel subfamily v member 2. Chain: a. Fragment: residues 75-326. Synonym: trpv2, osm-9-like trp channel 2, otrpc2, vanilloid receptor- like protein 1, vrl-1, stretch-activated channel 2b. Engineered: yes

Source:

Rattus norvegicus. Norway rat. Organism_taxid: 10116. Gene: trpv2, sac2b, vrl1. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

1.65Å R-factor: 0.189 R-free: 0.222

Authors:

X.Jin,R.Gaudet

Key ref:

X.Jin et al. (2006). Structure of the N-terminal ankyrin repeat domain of the TRPV2 ion channel. J Biol Chem, 281, 25006-25010. PubMed id: 16809337 DOI: 10.1074/jbc.C600153200

Date:

27-Oct-05 Release date: 27-Jun-06

Protein chain

Q9WUD2  (TRPV2_RAT) -  Transient receptor potential cation channel subfamily V member 2 from Rattus norvegicus

Seq: 761 a.a.

Struc: 252 a.a.*

* PDB and UniProt seqs differ at 6 residue positions (black crosses)

DOI no: 10.1074/jbc.C600153200

J Biol Chem 281:25006-25010 (2006)

PubMed id: 16809337

Structure of the N-terminal ankyrin repeat domain of the TRPV2 ion channel.

X.Jin, J.Touhey, R.Gaudet.

ABSTRACT

The TRPV ion channels mediate responses to many sensory stimuli including heat, low pH, neuropeptides, and chemical ligands. All TRPV subfamily members contain an intracellular N-terminal ankyrin repeat domain (ARD), a prevalent protein interaction motif. The 1.6-A crystal structure of the TRPV2-ARD, with six ankyrin repeats, reveals several atypical structural features. Repeats one through three display unusually long and flexible fingers with a large number of exposed aromatic residues, whereas repeats five and six have unusually long outer helices. Furthermore, a large counterclockwise twist observed in the stacking of repeats four and five breaks the regularity of the domain, altering the shape of surfaces available for interactions with proteins or other cellular ligands. Both solution studies and crystal packing interactions indicate that the TRPV2-ARD does not form homo-oligomers, suggesting that the ARD of TRPV ion channels may be used for interactions with regulatory factors rather than in promoting tetrameric assembly of the ion channels.

Selected figure(s)

Figure 1.
FIGURE 1. The TRPV2-ARD structure. A, primary structure of TRPV2. Ankyrin repeats are shown in labeled gray boxes; starred repeats are not recognized by sequence motif searches. B, left: Coomassie-stained gel of 2.5 µg of each of the three final protein samples used in crystallization, constructs 62-326, 75-321 (Se-Met substituted), and 75-321. Right: representative size exclusion chromatography trace of construct 75–321 on a Superdex 200 10/30 column. Arrows indicate elution volumes of molecular mass standards (molecular mass in kDa). C, ribbon diagram of TRPV2-ARD showing each ankyrin repeat in a distinct color. D, superposition of TRPV2-ARD structures. For clarity, only one chain from each crystal form is shown. Regions showing the most variability are colored green, gold, and blue for crystal forms I, II, and III, respectively. E, a large number of aromatic residues (shown in purple) are concentrated on the solvent-exposed surface of fingers 2 and 3.

Figure 2.
FIGURE 2. Structure-based sequence alignment of the six ankyrin repeats of TRPV2. A, a consensus ankyrin repeat sequence (16) is shown at the top, with designating a non-polar residue and x any residue. -Helices are red and 3[10] helices blue. Residues identical to consensus counterparts are boxed gray, showing a high level of conservation of a glycine at the second position and aliphatic residues in the inner and outer helices. The numbers in the last column are the lengths of inner/outer helices. B, superposition of repeats 1–4 of TRPV2-ARD (gold) and ankyrin (red, 1N11 (27); repeats 16–21 shown) highlights the large twist between repeats 4 and 5 of TRPV2-ARD.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2006, 281, 25006-25010) copyright 2006.

Figures were selected by the author.