PDBsum entry 1x6r

Structural protein

PDB id: 1x6r

Contents

Protein chain

120 a.a. *

Waters ×82

* Residue conservation analysis

PDB id:

1x6r

Name:

Structural protein

Title:

Structure 5: room temperature crystal structure of the truncated pak pilin from pseudomonas aeruginosa at 1.80a resolution

Structure:

Fimbrial protein. Chain: a. Synonym: pilin, strain pak. Engineered: yes

Source:

Pseudomonas aeruginosa. Organism_taxid: 287. Strain: k. Cellular_location: extracellular filamentous appendage. Gene: pila, fima. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693.

Resolution:

1.82Å R-factor: 0.151 R-free: 0.177

Authors:

K.V.Dunlop,R.T.Irvin,B.Hazes

Key ref:

K.V.Dunlop et al. (2005). Pros and cons of cryocrystallography: should we also collect a room-temperature data set? Acta Crystallogr D Biol Crystallogr, 61, 80-87. PubMed id: 15608379 DOI: 10.1107/S0907444904027179

Date:

11-Aug-04 Release date: 19-Apr-05

Protein chain

P02973  (FMPA_PSEAI) -  Fimbrial protein from Pseudomonas aeruginosa

Seq: 150 a.a.

Struc: 120 a.a.*

* PDB and UniProt seqs differ at 4 residue positions (black crosses)

DOI no: 10.1107/S0907444904027179

Acta Crystallogr D Biol Crystallogr 61:80-87 (2005)

PubMed id: 15608379

Pros and cons of cryocrystallography: should we also collect a room-temperature data set?

K.V.Dunlop, R.T.Irvin, B.Hazes.

ABSTRACT

High-resolution protein structures are becoming more common owing to the availability of increasingly brilliant synchrotron X-ray sources. However, to withstand the increased X-ray dose the crystals must be held at cryogenic temperatures. To compare the benefit of increased resolution with the drawback of potential temperature-induced changes, three room-temperature and three cryogenic data sets for PAK pilin have been collected at resolutions between 1.8 and 0.78 A. The results show that although the high-resolution cryogenic structures are more precise and more detailed, they also show systematic deviations from the room-temperature structures. Small but significant differences are even observed in the structural core, whilst more extensive changes occur at the protein surface. These differences can affect biological interpretations, especially because many important biological processes take place at the protein surface. Accordingly, although high-quality cryogenic synchrotron data is extremely valuable to protein crystallography, room-temperature structures are still desirable, especially if the research question involves protein features that are sensitive to temperature-induced changes.

Selected figure(s)

Figure 3.
Figure 3 2F[o] - F[c] density for Glu27 contoured at 1 . Density for structure 3 (yellow) shows two Glu27 side-chain conformations. Density for structure 4 (green) shows only one side-chain conformation. Structures 3 and 4 are representative of all cryocooled and all room-temperature structures, respectively. The figure was produced using Xfit (McRee, 1999[McRee, D. E. (1999). J. Struct. Biol. 125, 156-165.]) and Raster3D (Merritt & Murphy, 1994[Merritt, E. A. & Murphy, M. E. P. (1994). Acta Cryst. D50, 869-873.]).

Figure 4.
Figure 4 Ball-and-stick model showing superimposed cryocooled (green) and room-temperature (dark blue) water molecules for all six PAK structures within a small section of the PAK protein. The structure shows that waters observed in room-temperature structures are also present in cryocooled structures but not vice versa. The figure was made using Xfit (McRee, 1999[McRee, D. E. (1999). J. Struct. Biol. 125, 156-165.]) and Raster3D (Merritt & Murphy, 1994[Merritt, E. A. & Murphy, M. E. P. (1994). Acta Cryst. D50, 869-873.]).

The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2005, 61, 80-87) copyright 2005.

Figures were selected by an automated process.