Disease relevance of kpsT

• Characterization of KpsT, the ATP-binding component of the ABC-transporter involved with the export of capsular polysialic acid in Escherichia coli K1 [1].
• Extensive sequence homology between the KpsM and KpsT proteins and the products of the bexB and bexA genes present in the capsulation (cap) locus of Haemophilus influenzae, indicates that a common mechanism for the export of polysaccharide across the inner membrane may exist in these two micro-organisms [2].
• Analysis of the predicted amino acid sequence of the KpsM and KpsT proteins indicates that they may function as dual components in a polysaccharide export system analogous to the periplasmic binding protein-dependent transport systems of Gram-negative bacteria [2].

High impact information on kpsT

• The derivatization of KpsT by this reagent is inhibited by cold ATP or ATP gamma S. Furthermore, the protein seems to require a membrane environment for efficient photolabeling, but does not require any other kps gene products [1].
• Results obtained from saturation mutagenesis of the ATP-binding consensus sequence of KpsT and the phenotypes of strains with defined mutations in the chromosomal gene, are consistent with the view that ATP-binding by KpsT is required for transport of polymer across the inner membrane [1].
• RfbD and RfbE were similar to capsular polysaccharide export proteins, e.g. KpsM and KpsT of Escherichia coli [3].
• We propose that the KpsT protein acts as an energizer, coupling ATP hydrolysis to the transport process mediated by the KpsM protein [2].
• Evidence that KpsT, the ATP-binding component of an ATP-binding cassette transporter, is exposed to the periplasm and associates with polymer during translocation of the polysialic acid capsule of Escherichia coli K1 [4].

Anatomical context of kpsT

• We propose that KpsM and KpsT constitute a system for transport of polysialic acid across the cytoplasmic membrane [5].

Associations of kpsT with chemical compounds

• The KpsC, KpsS, and KpsT proteins involved in polysaccharide transport were associated with the inner membrane and this membrane association occurred in the absence of any other capsule-related proteins [6].
• All mutations mapped to the same glutamic acid residue at position 150, adjacent to Walker motif B of KpsT [7].

Other interactions of kpsT

• The KfiA and KfiC, together with the KpsC, KpsS and KpsT proteins, were purified and polyclonal antisera to each protein generated [6].

Analytical, diagnostic and therapeutic context of kpsT

• Results of site-directed mutagenesis of the putative ATP-binding domain of KpsT are consistent with the view that KpsT is a nucleotide-binding protein [5].

References