ClpL is a chaperone without auxiliary factors

Academic Article


  • 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 Streptococcus pneumoniae (pneumococcus), was biochemically characterized in vitro. 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.
  • Authors

    Digital Object Identifier (doi)

    Pubmed Id

  • 10834116
  • Author List

  • Park SS; Kwon HY; Tran TDH; Choi MH; Jung SH; Lee S; Briles DE; Rhee DK
  • Start Page

  • 1352
  • End Page

  • 1367
  • Volume

  • 282
  • Issue

  • 8