TY - JOUR
T1 - The sodium/proline transporter PutP of Helicobacter pylori
AU - Rivera-Ordaz, Araceli
AU - Bracher, Susanne
AU - Sarrach, Sannia
AU - Li, Zheng
AU - Shi, Lei
AU - Quick, Matthias
AU - Hilger, Daniel
AU - Haas, Rainer
AU - Jung, Heinrich
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2013/12/17
Y1 - 2013/12/17
N2 - 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,Lproline and L-azetidine-2-carboxylic acid.
AB - 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,Lproline and L-azetidine-2-carboxylic acid.
UR - http://www.scopus.com/inward/record.url?scp=84892916355&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84892916355&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0083576
DO - 10.1371/journal.pone.0083576
M3 - Article
C2 - 24358297
AN - SCOPUS:84892916355
VL - 8
JO - PLoS ONE
JF - PLoS ONE
SN - 1932-6203
IS - 12
M1 - e83576
ER -