This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Fukui, T. Articles by Imanaka, T. Search for Related Content PubMed PubMed Citation Articles by Fukui, T. Articles by Imanaka, T.

A Membrane-Bound Archaeal Lon Protease Displays ATP-Independent Proteolytic Activity towards Unfolded Proteins and ATP-Dependent Activity for Folded Proteins

Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, and Core Research for Evolutional Science and Technology Program of Japan Science and Technology Corporation, Kawaguchi, Saitama 332-0012, Japan

Received 19 November 2001/ Accepted 12 April 2002

In contrast to the eucaryal 26S proteasome and the bacterial ATP-dependent proteases, little is known about the energy-dependent proteolysis in members of the third domain, Archaea. We cloned a gene homologous to ATP-dependent Lon protease from a hyperthermophilic archaeon and observed the unique properties of the archaeal Lon. Lon from Thermococcus kodakaraensis KOD1 (Lon_Tk) is a 70-kDa protein with an N-terminal ATPase domain belonging to the AAA⁺ superfamily and a C-terminal protease domain including a putative catalytic triad. Interestingly, a secondary structure prediction suggested the presence of two transmembrane helices within the ATPase domain and Western blot analysis using specific antiserum against the recombinant protein clearly indicated that Lon_Tk was actually a membrane-bound protein. The recombinant Lon_Tk possessed thermostable ATPase activity and peptide cleavage activity toward fluorogenic peptides with optimum temperatures of 95 and 70°C, respectively. Unlike the enzyme from Escherichia coli, we found that Lon_Tk showed higher peptide cleavage activity in the absence of ATP than it did in the presence of ATP. When three kinds of proteins with different thermostabilities were examined as substrates, it was found that Lon_Tk required ATP for degradation of folded proteins, probably due to a chaperone-like function of the ATPase domain, along with ATP hydrolysis. In contrast, Lon_Tk degraded unfolded proteins in an ATP-independent manner, suggesting a mode of action in Lon_Tk different from that of its bacterial counterpart.

This article has been cited by other articles:

• Chen, S.-H., Suzuki, C. K., Wu, S.-H. (2008). Thermodynamic characterization of specific interactions between the human Lon protease and G-quartet DNA. Nucleic Acids Res 36: 1273-1287 [Abstract] [Full Text]  
• Ostersetzer, O., Kato, Y., Adam, Z., Sakamoto, W. (2007). Multiple Intracellular Locations of Lon Protease in Arabidopsis: Evidence for the Localization of AtLon4 to Chloroplasts. Plant Cell Physiol 48: 881-885 [Abstract] [Full Text]  
• Rohlin, L., Trent, J. D., Salmon, K., Kim, U., Gunsalus, R. P., Liao, J. C. (2005). Heat Shock Response of Archaeoglobus fulgidus. J. Bacteriol. 187: 6046-6057 [Abstract] [Full Text]  
• Yokoyama, H., Matsui, I. (2005). A Novel Thermostable Membrane Protease Forming an Operon with a Stomatin Homolog from the Hyperthermophilic Archaebacterium Pyrococcus horikoshii. J. Biol. Chem. 280: 6588-6594 [Abstract] [Full Text]  
• Im, Y. J., Na, Y., Kang, G. B., Rho, S.-H., Kim, M.-K., Lee, J. H., Chung, C. H., Eom, S. H. (2004). The Active Site of a Lon Protease from Methanococcus jannaschii Distinctly Differs from the Canonical Catalytic Dyad of Lon Proteases. J. Biol. Chem. 279: 53451-53457 [Abstract] [Full Text]  
• Lee, A. Y.-L., Hsu, C.-H., Wu, S.-H. (2004). Functional Domains of Brevibacillus thermoruber Lon Protease for Oligomerization and DNA Binding: ROLE OF N-TERMINAL AND SENSOR AND SUBSTRATE DISCRIMINATION DOMAINS. J. Biol. Chem. 279: 34903-34912 [Abstract] [Full Text]  
• Shockley, K. R., Ward, D. E., Chhabra, S. R., Conners, S. B., Montero, C. I., Kelly, R. M. (2003). Heat Shock Response by the Hyperthermophilic Archaeon Pyrococcus furiosus. Appl. Environ. Microbiol. 69: 2365-2371 [Abstract] [Full Text]