Structures of Brucella ovis leucine-, isoleucine-, valine-, threonine- and alanine-binding protein reveal a conformationally flexible peptide-binding cavity

Acta Crystallogr F Struct Biol Commun. 2024 Sep 1;80(Pt 9):193-199. doi: 10.1107/S2053230X24007027. Epub 2024 Aug 23.

Abstract

Brucella ovis is an etiologic agent of ovine epididymitis and brucellosis that causes global devastation in sheep, rams, goats, small ruminants and deer. There are no cost-effective methods for the worldwide eradication of ovine brucellosis. B. ovis and other protein targets from various Brucella species are currently in the pipeline for high-throughput structural analysis at the Seattle Structural Genomics Center for Infectious Disease (SSGCID), with the aim of identifying new therapeutic targets. Furthermore, the wealth of structures generated are effective tools for teaching scientific communication, structural science and biochemistry. One of these structures, B. ovis leucine-, isoleucine-, valine-, threonine- and alanine-binding protein (BoLBP), is a putative periplasmic amino acid-binding protein. BoLBP shares less than 29% sequence identity with any other structure in the Protein Data Bank. The production, crystallization and high-resolution structures of BoLBP are reported. BoLBP is a prototypical bacterial periplasmic amino acid-binding protein with the characteristic Venus flytrap topology of two globular domains encapsulating a large central cavity containing the peptide-binding region. The central cavity contains small molecules usurped from the crystallization milieu. The reported structures reveal the conformational flexibility of the central cavity in the absence of bound peptides. The structural similarity to other LBPs can be exploited to accelerate drug repurposing.

Keywords: SSGCID; brucellosis; drug repurposing; epididymitis; structural genomics; transport protein.

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins* / chemistry
  • Bacterial Proteins* / genetics
  • Bacterial Proteins* / metabolism
  • Binding Sites
  • Brucella ovis* / chemistry
  • Brucella ovis* / genetics
  • Brucella ovis* / metabolism
  • Crystallography, X-Ray
  • Models, Molecular
  • Peptides / chemistry
  • Peptides / metabolism
  • Protein Binding
  • Protein Conformation

Substances

  • Bacterial Proteins
  • Peptides