PDBsum entry 2avp

De novo protein

PDB id: 2avp

Contents

Protein chain

68 a.a. *

Metals

_CD ×2

Waters ×24

* Residue conservation analysis

PDB id:

2avp

Name:

De novo protein

Title:

Crystal structure of an 8 repeat consensus tpr superhelix

Structure:

Synthetic consensus tpr protein. Chain: a. Engineered: yes

Source:

Synthetic: yes. Other_details: the sequence of the protein was designed and then expressed in e.Coli bl21(de3), plasmid pproex-htb

Resolution:

2.04Å R-factor: 0.205 R-free: 0.241

Authors:

T.Kajander,A.L.Cortajarena,E.R.Main,S.Mochrie,L.Regan

Key ref:

T.Kajander et al. (2007). Structure and stability of designed TPR protein superhelices: unusual crystal packing and implications for natural TPR proteins. Acta Crystallogr D Biol Crystallogr, 63, 800-811. PubMed id: 17582171 DOI: 10.1107/S0907444907024353

Date:

30-Aug-05 Release date: 13-Sep-05

Protein chain

No UniProt id for this chain

Struc: 68 a.a.

DOI no: 10.1107/S0907444907024353

Acta Crystallogr D Biol Crystallogr 63:800-811 (2007)

PubMed id: 17582171

Structure and stability of designed TPR protein superhelices: unusual crystal packing and implications for natural TPR proteins.

T.Kajander, A.L.Cortajarena, S.Mochrie, L.Regan.

ABSTRACT

The structure and stability of repeat proteins has been little studied in comparison to the properties of the more familiar globular proteins. Here, the structure and stability of designed tetratricopeptide-repeat (TPR) proteins is described. The TPR is a 34-amino-acid motif which adopts a helix-turn-helix structure and occurs as tandem repeats. The design of a consensus TPR motif (CTPR) has previously been described. Here, the crystal structures and stabilities of proteins that contain eight or 20 identical tandem repeats of the CTPR motif (CTPR8 and CTPR20) are presented. Both CTPR8 and CTPR20 adopt a superhelical overall structure. The structures of the different-length CTPR proteins are compared with each other and with the structures of natural TPR domains. Also, the unusual and perhaps unique crystal-packing interactions resulting in pseudo-infinite crystalline superhelices observed in the different crystal forms of CTPR8 and CTPR20 are discussed. Finally, it is shown that the thermodynamic behavior of CTPR8 and CTPR20 can be predicted from the behavior of other TPRs in this series using an Ising model-based analysis. The designed protein series CTPR2-CTPR20 covers the natural size repertoire of TPR domains and as such is an excellent model system for natural TPR proteins.

Selected figure(s)

Figure 7.
Figure 7 Schematic representation of the crystal-packing interactions between superhelical molecules. (a) As an example, in P4[1]2[1]2 there are two repeats (numbered 1-8) within the asymmetric unit (indicated as AU; red box). For this arrangement there are eight equally possible two-repeat arrangements for the asymmetric unit. (b) Schematic illustration of the stacking of helices between repeats of individual molecules. The first A-helix of the next molecule must always pack against the last repeat of the previous molecule and therefore the C-terminal capping helix must be displaced. (c) Ribbon representation of the superhelical stacking with each single repeat coloured yellow or blue.

Figure 8.
Figure 8 Alignment of repeats 3-10 of the TPR domain of OGT (red) with the tetragonal crystal structure of CTPR8 (blue).

The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2007, 63, 800-811) copyright 2007.

Figures were selected by an automated process.