Abstract
KcsA, a potassium channel from Streptomyces lividans, is a good model for probing the general working mechanism of potassium channels. To date, the physiological activator of KcsA is still unknown, but in vitro studies showed that it could be opened by lowering the pH of the cytoplasmic compartment to 4. The C-terminal domain (CTD, residues 112-160) was proposed to be the modulator for this pH-responsive event. Here, we support this proposal by examining the pH profiles of: (a) thermal stability of KcsA with and without its CTD and (b) aggregation properties of a recombinant fragment of CTD. We found that the presence of the CTD weakened and enhanced the stability of KcsA at acidic and basic pH values, respectively. In addition, the CTD fragment oligomerized at basic pH values with a transition profile close to that of channel opening. Our results are consistent with the CTD being a pH modulator. We propose herein a mechanism on how this domain may contribute to the pH-dependent opening of KcsA.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 29163-29169 |
| Number of pages | 7 |
| Journal | Journal of Biological Chemistry |
| Volume | 282 |
| Issue number | 40 |
| DOIs | |
| State | Published - Oct 5 2007 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biochemistry
Cite this
Characterization of the C-terminal domain of a potassium channel from Streptomyces lividans (KcsA). / Pau, Victor P T; Zhu, Yongfang; Yuchi, Zhiguang; Hoang, Quyen; Yang, Daniel S C.
In: Journal of Biological Chemistry, Vol. 282, No. 40, 05.10.2007, p. 29163-29169.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Characterization of the C-terminal domain of a potassium channel from Streptomyces lividans (KcsA)
AU - Pau, Victor P T
AU - Zhu, Yongfang
AU - Yuchi, Zhiguang
AU - Hoang, Quyen
AU - Yang, Daniel S C
PY - 2007/10/5
Y1 - 2007/10/5
N2 - KcsA, a potassium channel from Streptomyces lividans, is a good model for probing the general working mechanism of potassium channels. To date, the physiological activator of KcsA is still unknown, but in vitro studies showed that it could be opened by lowering the pH of the cytoplasmic compartment to 4. The C-terminal domain (CTD, residues 112-160) was proposed to be the modulator for this pH-responsive event. Here, we support this proposal by examining the pH profiles of: (a) thermal stability of KcsA with and without its CTD and (b) aggregation properties of a recombinant fragment of CTD. We found that the presence of the CTD weakened and enhanced the stability of KcsA at acidic and basic pH values, respectively. In addition, the CTD fragment oligomerized at basic pH values with a transition profile close to that of channel opening. Our results are consistent with the CTD being a pH modulator. We propose herein a mechanism on how this domain may contribute to the pH-dependent opening of KcsA.
AB - KcsA, a potassium channel from Streptomyces lividans, is a good model for probing the general working mechanism of potassium channels. To date, the physiological activator of KcsA is still unknown, but in vitro studies showed that it could be opened by lowering the pH of the cytoplasmic compartment to 4. The C-terminal domain (CTD, residues 112-160) was proposed to be the modulator for this pH-responsive event. Here, we support this proposal by examining the pH profiles of: (a) thermal stability of KcsA with and without its CTD and (b) aggregation properties of a recombinant fragment of CTD. We found that the presence of the CTD weakened and enhanced the stability of KcsA at acidic and basic pH values, respectively. In addition, the CTD fragment oligomerized at basic pH values with a transition profile close to that of channel opening. Our results are consistent with the CTD being a pH modulator. We propose herein a mechanism on how this domain may contribute to the pH-dependent opening of KcsA.
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UR - http://www.scopus.com/inward/citedby.url?scp=35748949258&partnerID=8YFLogxK
U2 - 10.1074/jbc.M703277200
DO - 10.1074/jbc.M703277200
M3 - Article
C2 - 17693406
AN - SCOPUS:35748949258
VL - 282
SP - 29163
EP - 29169
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 40
ER -