PDBsum entry 5klh

Membrane protein

PDB id: 5klh

Contents

Protein chains

221 a.a.

Ligands

SO4

Waters ×462

PDB id:

5klh

Name:

Membrane protein

Title:

Crystal structure of trypanosoma brucei procyclic specific surface antigen-2

Structure:

Surface glycoprotein. Chain: a, b. Fragment: residues 40-262. Engineered: yes

Source:

Trypanosoma brucei. Organism_taxid: 5691. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

1.65Å R-factor: 0.179 R-free: 0.214

Authors:

R.Ramaswamy,M.L.Parker,M.J.Boulanger

Key ref:

R.Ramaswamy et al. (2016). Structural characterization reveals a novel bilobed architecture for the ectodomains of insect stage expressed Trypanosoma brucei PSSA-2 and Trypanosoma congolense ISA. Protein Sci, 25, 2297-2302. PubMed id: 27671214

Date:

24-Jun-16 Release date: 05-Jul-17

Protein chains

Q26806  (Q26806_9TRYP) -  Surface glycoprotein from Trypanosoma brucei

Seq: 412 a.a.

Struc: 221 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Protein Sci 25:2297-2302 (2016)

PubMed id: 27671214

Structural characterization reveals a novel bilobed architecture for the ectodomains of insect stage expressed Trypanosoma brucei PSSA-2 and Trypanosoma congolense ISA.

R.Ramaswamy, S.Goomeshi Nobary, B.A.Eyford, T.W.Pearson, M.J.Boulanger.

ABSTRACT

African trypanosomiasis, caused by parasites of the genus Trypanosoma, is a complex of devastating vector-borne diseases of humans and livestock in sub-Saharan Africa. Central to the pathogenesis of African trypanosomes is their transmission by the arthropod vector, Glossina spp. (tsetse fly). Intriguingly, the efficiency of parasite transmission through the vector is reduced following depletion of Trypanosoma brucei Procyclic-Specific Surface Antigen-2 (TbPSSA-2). To investigate the underlying molecular mechanism of TbPSSA-2, we determined the crystal structures of its ectodomain and that of its homolog T. congolense Insect Stage Antigen (TcISA) to resolutions of 1.65 Å and 2.45 Å, respectively using single wavelength anomalous dispersion. Both proteins adopt a novel bilobed architecture with the individual lobes displaying rotational flexibility around the central tether that suggest a potential mechanism for coordinating a binding partner. In support of this hypothesis, electron density consistent with a bound peptide was observed in the inter-lob cleft of a TcISA monomer. These first reported structures of insect stage transmembrane proteins expressed by African trypanosomes provide potentially valuable insight into the interface between parasite and tsetse vector.