title: The sodium/proline transporter PutP of Helicobacter pylori.
abstract: Helicobacter pylori is cause of chronic gastritis, duodenal ulcer and gastric carcinoma in humans. L-proline is a preferred energy source of the microaerophilic bacterium. Previous analyses revealed that HpputP and HpputA, the genes that are predicted to play a central role in proline metabolism as they encode for the proline transporter and proline dehydrogenase, respectively, are essential for stomach colonization. Here, the molecular basis of proline transport in H. pylori by HpPutP was investigated experimentally for the first time. Measuring radiolabeled substrate transport in H. pylori and E. coli heterologously expressing HpputP as well as in proteoliposomes reconstituted with HpPutP, we demonstrate that the observed proline transport in H. pylori is mediated by HpPutP. HpPutP is specific and exhibits a high affinity for L-proline. Notably, L-proline transport is exclusively dependent on Na(+) as coupling ion, i.e., Na(+)/L-proline symport, reminiscent to the properties of PutP of E. coli even though H. pylori lives in a more acidic environment. Homology model-based structural comparisons and substitution analyses identified amino acids crucial for function. HpPutP-catalyzed proline uptake was efficiently inhibited by the known proline analogs 3,4-dehydro-D,L-proline and L-azetidine-2-carboxylic acid.
authors.affiliation: Microbiology, Department of Biology I, Ludwig Maximilians University Munich, Martinsried, Germany.
authors.forename: Araceli
authors.initials: A
authors.lastname: Rivera-Ordaz
authors.affiliation: Microbiology, Department of Biology I, Ludwig Maximilians University Munich, Martinsried, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Bracher
authors.affiliation: Microbiology, Department of Biology I, Ludwig Maximilians University Munich, Martinsried, Germany.
authors.forename: Sannia
authors.initials: S
authors.lastname: Sarrach
authors.affiliation: Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, United States of America.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, United States of America ; HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medical College, New York, New York, United States of America.
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
authors.affiliation: Center for Molecular Recognition and Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, New York, United States of America.
authors.forename: Matthias
authors.initials: M
authors.lastname: Quick
authors.affiliation: Microbiology, Department of Biology I, Ludwig Maximilians University Munich, Martinsried, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Hilger
authors.affiliation: Max von Pettenkofer Institute for Hygiene and Medical Microbiology, Ludwig Maximilians University Munich, Munich, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Haas
authors.affiliation: Microbiology, Department of Biology I, Ludwig Maximilians University Munich, Martinsried, Germany.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Jung
mesh_terms: D026921:Amino Acid Transport Systems, Neutral / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001665:Binding Sites; D001692:Biological Transport; D029968:Escherichia coli Proteins / Q000235:genetics; D016480:Helicobacter pylori / Q000235:genetics* / Q000378:metabolism; D008958:Models, Molecular; D011392:Proline / Q000378:metabolism*; D017385:Sequence Homology; D012964:Sodium / Q000378:metabolism*; D013329:Structure-Activity Relationship; D027981:Symporters / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D026921:Amino Acid Transport Systems, Neutral; D029968:Escherichia coli Proteins; D027981:Symporters; C060609:PutP protein, E coli; D011392:Proline; D012964:Sodium