title: Evolutionary diversification of the trypanosome haptoglobin-haemoglobin receptor from an ancestral haemoglobin receptor.
abstract: The haptoglobin-haemoglobin receptor of the African trypanosome species, Trypanosoma brucei, is expressed when the parasite is in the bloodstream of the mammalian host, allowing it to acquire haem through the uptake of haptoglobin-haemoglobin complexes. Here we show that in Trypanosoma congolense this receptor is instead expressed in the epimastigote developmental stage that occurs in the tsetse fly, where it acts as a haemoglobin receptor. We also present the structure of the T. congolense receptor in complex with haemoglobin. This allows us to propose an evolutionary history for this receptor, charting the structural and cellular changes that took place as it adapted from a role in the insect to a new role in the mammalian host.
authors.affiliation: Department of Biochemistry, University of Oxford, Oxford, United Kingdom.
authors.forename: Harriet
authors.initials: H
authors.lastname: Lane-Serff
authors.affiliation: Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Paula
authors.initials: P
authors.lastname: MacGregor
authors.affiliation: School of Veterinary Science, University of Bristol, Bristol, United Kingdom.|School of Biological Sciences, University of Bristol, Bristol, United Kingdom.
authors.forename: Lori
authors.initials: L
authors.lastname: Peacock
authors.affiliation: Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Olivia Js
authors.initials: OJ
authors.lastname: Macleod
authors.affiliation: School of Biological Sciences, University of Bristol, Bristol, United Kingdom.
authors.forename: Christopher
authors.initials: C
authors.lastname: Kay
authors.affiliation: School of Biological Sciences, University of Bristol, Bristol, United Kingdom.
authors.forename: Wendy
authors.initials: W
authors.lastname: Gibson
authors.affiliation: Department of Biochemistry, University of Oxford, Oxford, United Kingdom.
authors.forename: Matthew K
authors.identifier: 0000-0002-2870-1955
authors.initials: MK
authors.lastname: Higgins
authors.affiliation: Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Mark
authors.initials: M
authors.lastname: Carrington
mesh_terms: D000818:Animals; D018360:Crystallography, X-Ray; D019143:Evolution, Molecular; D006454:Hemoglobins / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D011487:Protein Conformation; D015800:Protozoan Proteins / Q000235:genetics*; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014348:Trypanosoma congolense / Q000235:genetics*; D014370:Tsetse Flies / Q000469:parasitology
chemical_list: D006454:Hemoglobins; D015800:Protozoan Proteins; D011956:Receptors, Cell Surface; C027079:hemoglobin-haptoglobin receptor
keywords: brucei; congolense; evolution; evolutionary biology; genomics; haptoglobin-haemoglobin receptor; infectious disease; microbiology; trypanosome