Endopeptidase Clp Explained

Endopeptidase Clp
Ec Number:3.4.21.92
Cas Number:110910-59-3
Width:270

Endopeptidase Clp (endopeptidase Ti, caseinolytic protease, protease Ti, ATP-dependent Clp protease, ClpP, Clp protease).[1] [2] [3] [4] This enzyme catalyses the following chemical reaction

Hydrolysis of proteins to small peptides in the presence of ATP and Mg2+.

This bacterial enzyme contains subunits of two types, ClpP, with peptidase activity, and the protein ClpA, with AAA+ ATPase activity. ClpP and ClpA are not evolutionarily related.

A fully assembled Clp protease complex has a barrel-shaped structure in which two stacked heptameric ring of proteolytic subunits (ClpP or ClpQ) are either sandwiched between two rings or single-caped by one ring of hexameric ATPase-active chaperon subunits (ClpA, ClpC, ClpE, ClpX, ClpY, or others).[5]

ClpXP is presented in almost all bacteria while ClpA is found in the Gram-negative bacteria, ClpC in Gram-Positive bacteria and cyanobacteria. ClpAP, ClpXP and ClpYQ coexist in E. coli while only ClpXP complex in present in humans as mitochondrial enzymes.[5] ClpYQ is another name for the HslVU complex, a heat shock protein complex thought to resemble the hypothetical ancestor of the proteasome.[6]

ATPase

The Hsp100 family of eukaryotic heat shock proteins is homologous to the ATPase-active chaperon subunits found in the Clp complex; as such the entire group is often referred to as the HSP100/Clp family. The family is usually broken into two parts, one being the ClpA/B family with two ATPase domains, and the other being ClpX and friends with only one such domain.[7] ClpA through E is put into the first group along with Hsp78/104, and ClpX and HSIU is put into the second group.

Many of the proteins are not associated with a protease and have functions other than proteolysis. ClpB (human CLPB "Hsp78", yeast Hsp104) break up insoluble protein aggregates in conjunction with DnaK/Hsp70. They are thought to function by threading client proteins through a small 20 Å (2 nm) pore, thereby giving each client protein a second chance to fold.[8] [9] [10] A member of the ClpA/B family termed ClpV is used in the bacterial T6SS.[11]

See also

Notes and References

  1. Gottesman S, Clark WP, Maurizi MR . The ATP-dependent Clp protease of Escherichia coli. Sequence of clpA and identification of a Clp-specific substrate . The Journal of Biological Chemistry . 265 . 14 . 7886–93 . May 1990 . 2186030 .
  2. Maurizi MR, Clark WP, Katayama Y, Rudikoff S, Pumphrey J, Bowers B, Gottesman S . Sequence and structure of Clp P, the proteolytic component of the ATP-dependent Clp protease of Escherichia coli . The Journal of Biological Chemistry . 265 . 21 . 12536–45 . July 1990 . 2197275 .
  3. Book: Maurizi MR, Thompson MW, Singh SK, Kim SH . Endopeptidase Clp: ATP-dependent Clp protease from Escherichia coli . Methods in Enzymology . 244 . 314–31 . 1994 . 7845217 . 10.1016/0076-6879(94)44025-5 .
  4. Kessel M, Maurizi MR, Kim B, Kocsis E, Trus BL, Singh SK, Steven AC . Homology in structural organization between E. coli ClpAP protease and the eukaryotic 26 S proteasome . Journal of Molecular Biology . 250 . 5 . 587–94 . July 1995 . 7623377 . 10.1006/jmbi.1995.0400 .
  5. Hamon MP, Bulteau AL, Friguet B . Mitochondrial proteases and protein quality control in ageing and longevity . Ageing Research Reviews . 23 . Pt A . 56–66 . September 2015 . 25578288 . 10.1016/j.arr.2014.12.010 . 205667759 .
  6. Gille C, Goede A, Schlöetelburg C, Preissner R, Kloetzel PM, Göbel UB, Frömmel C . A comprehensive view on proteasomal sequences: implications for the evolution of the proteasome . Journal of Molecular Biology . 326 . 5 . 1437–48 . March 2003 . 12595256 . 10.1016/s0022-2836(02)01470-5 .
  7. Schirmer EC, Glover JR, Singer MA, Lindquist S . HSP100/Clp proteins: a common mechanism explains diverse functions . Trends in Biochemical Sciences . 21 . 8 . 289–96 . August 1996 . 8772382 . 10.1016/S0968-0004(96)10038-4 .
  8. Doyle SM, Wickner S . Hsp104 and ClpB: protein disaggregating machines . Trends in Biochemical Sciences . 34 . 1 . 40–8 . January 2009 . 19008106 . 10.1016/j.tibs.2008.09.010 .
  9. Horwich AL . Chaperoned protein disaggregation--the ClpB ring uses its central channel . Cell . 119 . 5 . 579–81 . November 2004 . 15550237 . 10.1016/j.cell.2004.11.018 . free .
  10. Weibezahn J, Tessarz P, Schlieker C, Zahn R, Maglica Z, Lee S, Zentgraf H, Weber-Ban EU, Dougan DA, Tsai FT, Mogk A, Bukau B . 6 . Thermotolerance requires refolding of aggregated proteins by substrate translocation through the central pore of ClpB . Cell . 119 . 5 . 653–65 . November 2004 . 15550247 . 10.1016/j.cell.2004.11.027 . free .
  11. Schlieker C, Zentgraf H, Dersch P, Mogk A . ClpV, a unique Hsp100/Clp member of pathogenic proteobacteria . Biological Chemistry . 386 . 11 . 1115–27 . November 2005 . 16307477 . 10.1515/BC.2005.128 . 34095247 .

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