1blf | pdb_00001blf
STRUCTURE OF DIFERRIC BOVINE LACTOFERRIN AT 2.8 ANGSTROMS RESOLUTION
Structural highlights
Function[TRFL_BOVIN] Transferrins are iron binding transport proteins which can bind two Fe(3+) ions in association with the binding of an anion, usually bicarbonate.[1] [2] Lactotransferrin has antimicrobial activity. The most effective inhibitory activity was seen against E.coli and P.aeruginosa.[3] [4] Lactoferricin B is an antimicrobial peptide. Inhibits the growth of Gram-negative and Gram-positive bacteria.[5] [6] The lactotransferrin transferrin-like domain 1 functions as a serine protease of the peptidase S60 family that cuts arginine rich regions. This function contributes to the antimicrobial activity.[7] [8] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe three-dimensional structure of diferric bovine lactoferrin (bLf) has been determined by X-ray crystallography in order to investigate the factors that influence iron binding and release by transferrins. The structure was solved by molecular replacement, using the coordinates of diferric human lactoferrin (hLf) as a search model, and was refined with data to 2.8 A resolution by simulated annealing (X-PLOR) and restrained least squares (TNT). The final model comprises 5310 protein atoms (residues 5 to 689), 124 carbohydrate atoms (from ten monosaccharide units, in three glycan chains), 2 Fe3+, 2 CO32- and 50 water molecules. This model gives an R-factor of 0.232 for 21440 reflections in the resolution range 30.0 to 2.8 A. The folding of the bLf molecule is essentially the same as that of hLf, but bLf differs in the extent of closure of the two domains of each lobe, and in the relative orientations of the two lobes. Differences in domain closure are attributed to amino acid changes in the interface, and differences in lobe orientations to slightly altered packing of two hydrophobic patches between the lobes. Changed interdomain interactions may explain the lesser iron affinity of bLf, compared with hLf, and two lysine residues behind the N-lobe iron site of bLf offer new insights into the "dilysine trigger" mechanism proposed for iron release by transferrins. The bLf structure is also notable for several well-defined oligosaccharide units which demonstrate the structural factors that stabilise carbohydrate structure. One glycan chain, attached to Asn545, appears to contribute to interdomain interactions and may modulate iron release from the C-lobe. Three-dimensional structure of diferric bovine lactoferrin at 2.8 A resolution.,Moore SA, Anderson BF, Groom CR, Haridas M, Baker EN J Mol Biol. 1997 Nov 28;274(2):222-36. PMID:9398529[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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