ClpL is a chaperone without auxiliary factors. (27th February 2015)

• Record Type: Journal Article
• Authors: Park, Sang‐Sang; Kwon, Hyog‐Young; Tran, Thao Dang‐Hien; Choi, Moo‐Hyun; Jung, Seung‐Ha; Lee, Sangho; Briles, David E.; Rhee, Dong‐Kwon
• Is Part Of: FEBS journal. Volume 282:Number 8(2015)
• Page Start: 1352
• Page End: 1367
• Publication Date: 2015-02-27
• Subjects: Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pathology, Molecular -- Periodicals; 572
• DOI: 10.1111/febs.13228
• Languages: English
• ISSNs: 1742-464X

Abstract

<abstract abstract-type="main" id="febs13228-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Caseinolytic protease L (ClpL) is a member of the heat shock protein (Hsp) 100 family, which is found mostly in Gram‐positive bacteria. Here, ClpL, a major HSP in <italic>Streptococcus pneumoniae</italic> (pneumococcus), was biochemically characterized <italic>in vitro</italic>. Recombinant ClpL shows nucleotide hydrolase, refolding, holdase and disaggregation activity using either Mg²⁺ or Mn²⁺ and does not require the DnaK system for chaperone activity. ClpL exhibits two features distinct from other HSP100 family proteins: (a) Mn²⁺ enhances hydrolase activity, as well as chaperone activity; and (b) NTPase activity. ClpL forms a hexamer in the presence of ADP, ATP and ATP‐γ‐S. Mutational analysis using double‐mutant proteins mutated at the two Walker A motifs (K127A/T128A and K458A/T459A) revealed that both nucleotide‐binding domains are involved in chaperone activity, ATP hydrolase activity and hexamerization. Overall, pneumococcal ClpL is a unique Mn²⁺‐dependent Hsp100 family member that has chaperone activity without other co‐chaperones.</p> </abstract>