PDBsum entry 1ce2

Metal transport

PDB id: 1ce2

Contents

Protein chain

689 a.a. *

Ligands

CO3 ×2

Metals

_FE ×2

Waters ×91

* Residue conservation analysis

PDB id:

1ce2

Name:

Metal transport

Title:

Structure of diferric buffalo lactoferrin at 2.5a resolution

Structure:

Protein (lactoferrin). Chain: a

Source:

Bubalus bubalis. Water buffalo. Organism_taxid: 89462. Secretion: milk. Cellular_location: extracellular

Resolution:

2.50Å R-factor: 0.187 R-free: 0.265

Authors:

S.Karthikeyan,M.Paramasivam,S.Yadav,A.Srinivasan,T.P.Singh

Key ref:

S.Karthikeyan et al. (1999). Structure of buffalo lactoferrin at 2.5 A resolution using crystals grown at 303 K shows different orientations of the N and C lobes. Acta Crystallogr D Biol Crystallogr, 55, 1805-1813. PubMed id: 10531476 DOI: 10.1107/S0907444999010951

Date:

13-Mar-99 Release date: 19-Mar-99

Protein chain

O77698  (TRFL_BUBBU) -  Lactotransferrin from Bubalus bubalis

Seq: 708 a.a.

Struc: 689 a.a.*

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

Enzyme reactions

• Enzyme class: E.C.3.4.21.- - ?????

DOI no: 10.1107/S0907444999010951

Acta Crystallogr D Biol Crystallogr 55:1805-1813 (1999)

PubMed id: 10531476

Structure of buffalo lactoferrin at 2.5 A resolution using crystals grown at 303 K shows different orientations of the N and C lobes.

S.Karthikeyan, M.Paramasivam, S.Yadav, A.Srinivasan, T.P.Singh.

ABSTRACT

The structure of buffalo lactoferrin has been determined at 303 K. The crystals belong to orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 77.5, b = 91.0, c = 131.5 A and Z = 4. The structure has been refined to an R factor of 0.187. The overall structure of the protein is similar to its structure determined at 277 K in a different crystal form. However, the lobe orientations in the two structures differ by 9.0 degrees, suggesting significant inter-lobe flexibility in this family of proteins. The inter-lobe interactions are predominantly hydrophobic and could act as a cushion for a change in orientation under the influence of external conditions. On the other hand, the domain arrangements are found to be similar in 277 and 303 K crystal structures, with orientations differing by 1.5 and 1.0 degrees in the N and C lobes, respectively. The results of these investigations suggest that the increase in temperature helps in the production of better quality crystals.

Selected figure(s)

Figure 4.
Figure 4 Stereoview of the 2F[o] - F[c] electron-density map at the iron-binding site for the N lobe. The electron density at the C lobe iron-binding site is very similar. The map is contoured at 1.2 .

Figure 7.
Figure 7 Stereoview of the environment behind the metal-binding site in the N lobe, showing the interactions of Lys210 and Lys301. Lys210 froms a hydrogen bond to Tyr192 and Tyr82 through a water molecule which is conserved in lactoferrins. Lys301 interacts with Glu216, Asp297 and the carbonyl O atom of Asp302. In transferrins, the corresponding Lys209 and Lys301 interact to form a so-called Lys-Lys trigger.

The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (1999, 55, 1805-1813) copyright 1999.

Figures were selected by an automated process.