Abstract：
:Chaperone-proteases are responsible for the processive breakdown of proteins in eukaryotic, archaeal and bacterial cells. They are composed of a cylinder-shaped protease lined on the interior with proteolytic sites and of ATPase rings that bind to the apical sides of the protease to control substrate entry. We present a real-time FRET-based method for probing the reaction cycle of chaperone-proteases, which consists of substrate unfolding, translocation into the protease and degradation. Using this system we show that the two alternative bacterial ClpAP and ClpXP complexes share the same mechanism: after initial tag recognition, fast unfolding of substrate occurs coinciding with threading through the chaperone. Subsequent slow substrate translocation into the protease chamber leads to formation of a transient compact substrate intermediate presumably close to the chaperone-protease interface. Our data for ClpX and ClpA support the mechanical unfolding mode of action proposed for these chaperones. The general applicability of the designed FRET system is demonstrated here using in addition an archaeal PAN-proteasome complex as model for the more complex eukaryotic proteasome.
journal_name
J Struct Bioljournal_title
Journal of structural biologyauthors
Kolygo K,Ranjan N,Kress W,Striebel F,Hollenstein K,Neelsen K,Steiner M,Summer H,Weber-Ban Edoi
10.1016/j.jsb.2009.07.003subject
Has Abstractpub_date
2009-11-01 00:00:00pages
267-77issue
2eissn
1047-8477issn
1095-8657pii
S1047-8477(09)00177-4journal_volume
168pub_type
杂志文章abstract：:Teeth sustain high loads over a lifetime and yet intact tooth failure is rare. The different structures of the tooth, jaw bone and the intervening soft periodontal ligament enable the tooth to endure repeated loading during mastication. Although mechanical and functional properties of the different components are thor...
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journal_title：Journal of structural biology
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journal_title：Journal of structural biology
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journal_title：Journal of structural biology
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abstract：:RCK is a cytoplasmic regulatory domain of calcium-gated potassium channels. Binding of Ca(2+) by RCK leads to channel activation through a series of yet unknown conformational changes. Structures of the K(+) channel, MthK, and its cytoplasmic RCK domain revealed two binding sites for Ca(2+) per dimer. We determined th...
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journal_title：Journal of structural biology
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journal_title：Journal of structural biology
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journal_title：Journal of structural biology
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abstract：:Citropin 1.1 is a basic, highly hydrophobic, 16-amino acid peptide (GLFDVIKKVASVIGGL-NH(2)), displaying wide-spectrum antimicrobial activities. In this paper we describe the synthesis and antimicrobial properties of citropin 1.1 and its 18 analogs constituting mostly truncated fragments of citropin 1.1. Moreover, we e...
journal_title：Journal of structural biology
pub_type： 杂志文章
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更新日期：2009-11-01 00:00:00
