6VRI image
Deposition Date 2020-02-07
Release Date 2020-12-02
Last Version Date 2023-10-11
Entry Detail
PDB ID:
6VRI
Title:
Crystal Structure of the wtBlc-split Protein
Biological Source:
Source Organism:
Escherichia coli (Taxon ID: 562)
Method Details:
Experimental Method:
Resolution:
1.94 Å
R-Value Free:
0.24
R-Value Work:
0.21
R-Value Observed:
0.21
Space Group:
P 32 2 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Outer membrane lipoprotein Blc
Chain IDs:A, C, E
Chain Length:107
Number of Molecules:3
Biological Source:Escherichia coli
Polymer Type:polypeptide(L)
Molecule:Outer membrane lipoprotein Blc
Chain IDs:B, D, F
Chain Length:69
Number of Molecules:3
Biological Source:Escherichia coli
Primary Citation
Lipocalin Blc is a potential heme-binding protein.
Febs Lett. 595 206 219 (2021)
PMID: 33210733 DOI: 10.1002/1873-3468.14001

Abstact

Lipocalins are a superfamily of functionally diverse proteins defined by a well-conserved tertiary structure despite variation in sequence. Lipocalins bind and transport small hydrophobic molecules in organisms of all kingdoms. However, there is still uncertainty regarding the function of some members of the family, including bacterial lipocalin Blc from Escherichia coli. Here, we present evidence that lipocalin Blc may be involved in heme binding, trans-periplasmic transport, or heme storage. This conclusion is supported by a cocrystal structure, mass-spectrometric data, absorption titration, and in silico analysis. Binding of heme is observed at low micromolar range with one-to-one ligand-to-protein stoichiometry. However, the absence of classical coordination to the iron atom leaves the possibility that the primary ligand of Blc is another tetrapyrrole.

Legend

Protein

Chemical

Disease

Primary Citation of related structures