Improvement in K+-limited growth rate associated with expression of the N-terminal fragment of one subunit (kdpA) of the multisubunit kdp transporter in Escherichia coli

Sardesai, Abhijit A. ; Gowrishankar, J. (2001) Improvement in K+-limited growth rate associated with expression of the N-terminal fragment of one subunit (kdpA) of the multisubunit kdp transporter in Escherichia coli Journal of Bacteriology, 183 (11). pp. 3515-3520. ISSN 0021-9193

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Official URL: http://jb.asm.org/cgi/content/abstract/183/11/3515

Related URL: http://dx.doi.org/10.1128/JB.183.11.3515-3520.2001

Abstract

Mutations in any one of three genes, kdpA, -B, or -C, in Escherichia coli abolish the activity of Kdp, a multisubunit K+-ATPase that belongs to the P-type ATPase family of cation transporters. We found in this study that expression in vivo of a 135-amino-acid-long N-terminal fragment (KdpA'), less than one-quarter the length of native KdpA, was able to mediate an improvement in K+-limited growth rates in two different contexts, even in the absence of both KdpC and the ATPase subunit KdpB. The first context was when KdpA' was overexpressed in cells from a heterologous inducible promoter, and the second was when KdpA' was provided with a C-terminally altered extension (following a spontaneous genetic rearrangement). Our results suggest that KdpA' provides an incipient pathway for K+ translocation which can serve to transport K+ into the cells in response to the cytoplasmic membrane potential.

Item Type:Article
Source:Copyright of this article belongs to American Society for Microbiology.
ID Code:16932
Deposited On:16 Nov 2010 13:18
Last Modified:17 May 2016 01:38

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