| Title | Characteristics of Na^+ -dependent Serine Transport in Haemophilus Influenzae Rd |
|---|---|
| Author | Young-Mog Kim 1, *, In-Koo Rhee 1,2 , Mi-Yeon Park 3 , Dong-Suck Chang 3 , and Tomofusa Tsuchiya 4 |
| Address | 1 Institute of Agricultural Science & Technology and; 2 Department of Agricultural Chemistry, Kyungpook National University, Daegu 702-701, Korea; 3 Department of Food Science & Technology, Pukyong National University, Busan, 608-727, Korea; 4 Faculty of Pharmaceutical Science, Okayama University, Okayama, 700-8530, Japan (Received March 10, 2003 / Accepted May 13, 2003) |
| Bibliography | Journal of Microbiology, 41(2),78-82, 2003, |
| DOI | |
| Key Words | Haemophilus influenzae Rd, serine transport |
| Abstract | We identified two proteins in Haemophilus influenzae Rd that exhibited high similarity to two major serine transporters of Escherichia coli (SstT and SdaC). Then, we investigated serine transport in H. influenzae Rd and detected Na + -stimulated L-serine transport activity. The optimum NaCl concentration for this stimulation was about 20 mM. The uptake of Na^+ by H. influenzae Rd was found to be elicited by L-serine influx, which supports the idea that L-serine is transported by a mechanism of Na^+ / serine symport. No uptake of H + elicited by L-serine influx was detected. Na^+ /serine symport activity was not inhibited by other amino acids such as L-threonine or D-serine. Two distinct Km values were obtained from the kinetic analysis of serine transport. Thus, two serine transport pathways may exist in H. influenzae Rd, and it appears that both systems are stimulated by Na^+ . |
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