2z3p
From Proteopedia
(New page: 200px<br /><applet load="2z3p" size="350" color="white" frame="true" align="right" spinBox="true" caption="2z3p, resolution 2.50Å" /> '''complex structure of...) |
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==Overview== | ==Overview== | ||
| - | Eubacterial leucyl/phenylalanyl-tRNA protein transferase (LF-transferase) | + | Eubacterial leucyl/phenylalanyl-tRNA protein transferase (LF-transferase) catalyses peptide-bond formation by using Leu-tRNA(Leu) (or Phe-tRNA(Phe)) and an amino-terminal Arg (or Lys) of a protein, as donor and acceptor substrates, respectively. However, the catalytic mechanism of peptide-bond formation by LF-transferase remained obscure. Here we determine the structures of complexes of LF-transferase and phenylalanyl adenosine, with and without a short peptide bearing an N-terminal Arg. Combining the two separate structures into one structure as well as mutation studies reveal the mechanism for peptide-bond formation by LF-transferase. The electron relay from Asp 186 to Gln 188 helps Gln 188 to attract a proton from the alpha-amino group of the N-terminal Arg of the acceptor peptide. This generates the attacking nucleophile for the carbonyl carbon of the aminoacyl bond of the aminoacyl-tRNA, thus facilitating peptide-bond formation. The protein-based mechanism for peptide-bond formation by LF-transferase is similar to the reverse reaction of the acylation step observed in the peptide hydrolysis reaction by serine proteases. |
==About this Structure== | ==About this Structure== | ||
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[[Category: lf-transferase]] | [[Category: lf-transferase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:00:01 2008'' |
Revision as of 17:00, 21 February 2008
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complex structure of LF-transferase and leucine
Overview
Eubacterial leucyl/phenylalanyl-tRNA protein transferase (LF-transferase) catalyses peptide-bond formation by using Leu-tRNA(Leu) (or Phe-tRNA(Phe)) and an amino-terminal Arg (or Lys) of a protein, as donor and acceptor substrates, respectively. However, the catalytic mechanism of peptide-bond formation by LF-transferase remained obscure. Here we determine the structures of complexes of LF-transferase and phenylalanyl adenosine, with and without a short peptide bearing an N-terminal Arg. Combining the two separate structures into one structure as well as mutation studies reveal the mechanism for peptide-bond formation by LF-transferase. The electron relay from Asp 186 to Gln 188 helps Gln 188 to attract a proton from the alpha-amino group of the N-terminal Arg of the acceptor peptide. This generates the attacking nucleophile for the carbonyl carbon of the aminoacyl bond of the aminoacyl-tRNA, thus facilitating peptide-bond formation. The protein-based mechanism for peptide-bond formation by LF-transferase is similar to the reverse reaction of the acylation step observed in the peptide hydrolysis reaction by serine proteases.
About this Structure
2Z3P is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as Leucyltransferase, with EC number 2.3.2.6 Full crystallographic information is available from OCA.
Reference
Protein-based peptide-bond formation by aminoacyl-tRNA protein transferase., Watanabe K, Toh Y, Suto K, Shimizu Y, Oka N, Wada T, Tomita K, Nature. 2007 Oct 18;449(7164):867-71. Epub 2007 Sep 23. PMID:17891155
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