1q71
From Proteopedia
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| - | + | {{STRUCTURE_1q71| PDB=1q71 | SCENE= }} | |
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'''The structure of microcin J25 is a threaded sidechain-to-backbone ring structure and not a head-to-tail cyclized backbone''' | '''The structure of microcin J25 is a threaded sidechain-to-backbone ring structure and not a head-to-tail cyclized backbone''' | ||
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[[Category: Jones, A.]] | [[Category: Jones, A.]] | ||
[[Category: Rosengren, K J.]] | [[Category: Rosengren, K J.]] | ||
| - | [[Category: | + | [[Category: Antimicrobial peptide]] |
| - | [[Category: | + | [[Category: Mccj25]] |
| - | [[Category: | + | [[Category: Microcin j25]] |
| - | [[Category: | + | [[Category: Nmr]] |
| - | [[Category: | + | [[Category: Sidechain-to-backbone link]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 05:56:52 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 02:56, 3 May 2008
The structure of microcin J25 is a threaded sidechain-to-backbone ring structure and not a head-to-tail cyclized backbone
Overview
Microcin J25 is a 21 amino acid bacterial peptide that has potent antibacterial activity against Gram-negative bacteria, resulting from its interaction with RNA polymerase. The peptide was previously proposed to have a head-to-tail cyclized peptide backbone and a tight globular structure (Blond, A., Peduzzi, J., Goulard, C., Chiuchiolo, M. J., Barthelemy, M., Prigent, Y., Salomon, R. A., Farias, R. N., Moreno, F. & Rebuffat, S. Eur. J. Biochem. 1999, 259, 747-755). It exhibits remarkable thermal stability for a peptide of its size lacking disulfide bonds and in part this was previously proposed to derive from its macrocyclic structure. We show here that in fact the peptide does not have a head-to-tail cyclic structure but rather a side chain to backbone cyclization between Glu8 and the N-terminus. This creates an embedded ring that is threaded by the C-terminal tail of the molecule, forming a noose-like feature. The three-dimensional structure deduced from NMR data suggests that slippage of the noose is prevented by two aromatic residues flanking the embedded ring. Unthreading does not occur even when the molecule is enzymatically digested with thermolysin. The new structural interpretation fully accounts for previously reported NMR and biophysical data and is consistent with the remarkable stability of this potent antimicrobial peptide.
About this Structure
1Q71 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Microcin J25 has a threaded sidechain-to-backbone ring structure and not a head-to-tail cyclized backbone., Rosengren KJ, Clark RJ, Daly NL, Goransson U, Jones A, Craik DJ, J Am Chem Soc. 2003 Oct 15;125(41):12464-74. PMID:14531690 Page seeded by OCA on Sat May 3 05:56:52 2008
