PDBsum entry 1thw

Sweet tasting protein

PDB id: 1thw

Contents

Protein chain

207 a.a. *

Ligands

TLA

Waters ×105

* Residue conservation analysis

PDB id:

1thw

Name:

Sweet tasting protein

Title:

The structures of three crystal forms of the sweet protein thaumatin

Structure:

Thaumatin. Chain: a. Engineered: yes

Source:

Thaumatococcus daniellii. Miracle fruit. Organism_taxid: 4621

Resolution:

1.75Å R-factor: 0.181

Authors:

T.-P.Ko,J.Day,A.Greenwood,A.Mcpherson

Key ref:

T.P.Ko et al. (1994). Structures of three crystal forms of the sweet protein thaumatin. Acta Crystallogr D Biol Crystallogr, 50, 813-825. PubMed id: 15299348 DOI: 10.1107/S0907444994005512

Date:

10-Jun-94 Release date: 20-Dec-94

Protein chain

P02883  (THM1_THADA) -  Thaumatin I from Thaumatococcus daniellii

Seq: 235 a.a.

Struc: 207 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

DOI no: 10.1107/S0907444994005512

Acta Crystallogr D Biol Crystallogr 50:813-825 (1994)

PubMed id: 15299348

Structures of three crystal forms of the sweet protein thaumatin.

T.P.Ko, J.Day, A.Greenwood, A.McPherson.

ABSTRACT

Three crystal forms of the sweet-tasting protein thaumatin from the African berry Thaumatococcus daniellii have been grown. These include two naturally occurring isoforms, A and B, that differ by a single amino acid, and a recombinant form of isoform B expressed in yeast. The crystals are of space groups C2 with a = 117.7, b = 44.9, c = 38.0 A, and beta = 94.0 degrees, P2(1)2(1)2(1) with a = 44.3, b = 63.7 and c = 72.7 A, and a tetragonal form P4(1)2(1)2 with a = b = 58.6 and c = 151.8 A. The structures of all three crystals have been solved by molecular replacement and subsequently refined to R factors of 0.184 for the monoclinic at 2.6 A, 0.165 for the orthorhombic at 1.75 A, and 0.181 for the tetragonal, also at 1.75 A resolution. No solvent was included in the monoclinic crystal while 123 and 105 water molecules were included in the higher resolution orthorhombic and tetragonal structures, respectively. A bound tartrate molecule was also clearly visible in the tetragonal structure. The r.m.s. deviations between molecular structures in the three crystals range from 0.6 to 0.7 A for Calpha atoms, and 1.1 to 1.3 A for all atoms. This is comparable to the r.m.s. deviation between the three structures and the starting model. Nevertheless, several peptide loops show particularly large variations from the initial model.

Selected figure(s)

Figure 5.
Fig. 5.2Fo - Fc electron-density map for the bound tartrate in the -is0 --90 tetragonal crystal. The map was calculated as in Fig. 4. For clarity only a box of density sufficient to encompass the tartrate molecule is shown.. Similar density was also observed in the Fo-Fc map based on the original model. Also shown are nearby protein atoms. Seen labeled are the interacting groups from Lys137, Tyr157, Arg29 i, Ser36' and Lys67".

Figure 10.
Fig. 10. Superposition of all-atom models after refinement in the C2, P2~2~2t and P4~2~2 crystals, colored green, blue and red, respectively, on the original model, colored purple.

The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (1994, 50, 813-825) copyright 1994.

Figures were selected by an automated process.