|Gene:||pth||Accession Numbers: EG10785 (EcoCyc), b1204, ECK1192|
Peptidyl-tRNA hydrolase (Pth) catalyzes the removal of peptides from peptidyl-tRNAs that have been prematurely released from the ribosome. The enzyme is essential for growth in E. coli [Menninger79, Singh04]. lysV, encoding a tRNALys, was found to be a multicopy suppressor of a temperature sensitive pth mutant, indicating that the pth mutant phenotype is due to starvation for tRNALys [HeurgueHamard96, VivancoDomingue06]. In general, Pth relieves growth inhibition by freeing tRNAs from aborted translation products [Tenson99, Dincbas99]. Pth is also required for growth of bacteriophage lambda due to translation of minigene ORFs in the lambda bar region [Henderson76, Ontiveros97, Valadez01, Oviedo04].
The crystal structure of Pth has been solved at 1.2 Å resolution [Schmitt97, Schmitt97a]. Pth is monomeric. Predicted active site residues were confirmed by site-directed mutagenesis [Schmitt97a]. The His20 residue is essential for catalytic activity [Goodall04]. The catalytic center has been mapped by NMR [Giorgi11].
The integrity of ychF, the downstream open reading frame in the pth operon, influences the stability of the transcript. Lower RNase E activity results in overproduction of Pth, and thus it is proposed that RNase E processing within ychF causes mRNA degradation [CruzVera02].
A temperature-sensitive pth mutant was isolated [Atherly72, Menninger73]; the mutant protein is unstable in vivo [CruzVera00]. The mutant allele can revert rapidly by gene duplication [Menez01]. Overexpression of tmRNA can rescue the defect of the pthts allele [Singh04]. The rap mutant of Pth [Henderson76] is highly sensitive to the length of the peptidyl-tRNA [HeurgueHamard00].
|Map Position: [1,257,152 <- 1,257,736] (27.1 centisomes)||Length: 585 bp / 194 aa|
Molecular Weight of Polypeptide: 21.082 kD (from nucleotide sequence), 21.0 kD (experimental) [GarciaVillegas91 ]
pI: 10.0 [Dutka93]
Unification Links: ASAP:ABE-0004043 , CGSC:352 , DIP:DIP-35932N , EchoBASE:EB0778 , EcoGene:EG10785 , EcoliWiki:b1204 , Mint:MINT-1225563 , ModBase:P0A7D1 , OU-Microarray:b1204 , PortEco:pth , PR:PRO_000023628 , Pride:P0A7D1 , Protein Model Portal:P0A7D1 , RefSeq:NP_415722 , RegulonDB:EG10785 , SMR:P0A7D1 , String:511145.b1204 , UniProt:P0A7D1
Relationship Links: InterPro:IN-FAMILY:IPR001328 , InterPro:IN-FAMILY:IPR018171 , Panther:IN-FAMILY:PTHR17224 , PDB:Structure:2PTH , PDB:Structure:3VJR , Pfam:IN-FAMILY:PF01195 , Prosite:IN-FAMILY:PS01195 , Prosite:IN-FAMILY:PS01196
|Biological Process:||GO:0006515 - misfolded or incompletely synthesized protein catabolic process [Menninger79, Tenson99, Dincbas99]|
|Molecular Function:||GO:0004045 - aminoacyl-tRNA hydrolase activity
[GOA01a, GOA01, Schmitt97a]
GO:0016787 - hydrolase activity [UniProtGOA11]
|Cellular Component:||GO:0005737 - cytoplasm
GO:0005829 - cytosol
|MultiFun Terms:||information transfer → protein related → translation|
|Growth Medium||Growth?||T (°C)||O2||pH||Osm/L||Growth Observations|
|LB Lennox||No||37||Aerobic||7||No [Baba06, Comment 1]|
Enzymatic reaction of: peptidyl-tRNA hydrolase
Synonyms: aminoacyl-tRNA hydrolase, aminoacyl-transfer ribonucleate hydrolase, N-substituted aminoacyl transfer RNA hydrolase, aminoacyl-tRNA aminoacylhydrolase
EC Number: 188.8.131.52
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction of enzyme catalysis.
The reaction is physiologically favored in the direction shown.
3/2/1998 (pkarp) Merged genes G518/b1204 and EG10785/pth
10/20/97 Gene b1204 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10785; confirmed by SwissProt match.
Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554
Dincbas99: Dincbas V, Heurgue-Hamard V, Buckingham RH, Karimi R, Ehrenberg M (1999). "Shutdown in protein synthesis due to the expression of mini-genes in bacteria." J Mol Biol 291(4);745-59. PMID: 10452886
Dutka93: Dutka S, Meinnel T, Lazennec C, Mechulam Y, Blanquet S (1993). "Role of the 1-72 base pair in tRNAs for the activity of Escherichia coli peptidyl-tRNA hydrolase." Nucleic Acids Res 21(17);4025-30. PMID: 7690473
GarciaVillegas91: Garcia-Villegas MR, De La Vega FM, Galindo JM, Segura M, Buckingham RH, Guarneros G (1991). "Peptidyl-tRNA hydrolase is involved in lambda inhibition of host protein synthesis." EMBO J 10(11);3549-55. PMID: 1833189
Giorgi11: Giorgi L, Plateau P, O'Mahony G, Aubard C, Fromant M, Thureau A, Grotli M, Blanquet S, Bontems F (2011). "NMR-Based Substrate Analog Docking to Escherichia coli Peptidyl-tRNA Hydrolase." J Mol Biol 412(4);619-33. PMID: 21718701
Henderson76: Henderson D, Weil J (1976). "A mutant of Escherichia coli that prevents growth of phage lambda and is bypassed by lambda mutants in a nonessential region of the genome." Virology 71(2);546-59. PMID: 779235
HeurgueHamard96: Heurgue-Hamard V, Mora L, Guarneros G, Buckingham RH (1996). "The growth defect in Escherichia coli deficient in peptidyl-tRNA hydrolase is due to starvation for Lys-tRNA(Lys)." EMBO J 15(11);2826-33. PMID: 8654380
Menez01: Menez J, Remy E, Buckingham RH (2001). "Suppression of thermosensitive peptidyl-tRNA hydrolase mutation in Escherichia coli by gene duplication." Microbiology 147(Pt 6);1581-9. PMID: 11390689
Menninger73: Menninger JR, Walker C, Tan PF (1973). "Studies on the metabolic role of peptidyl-tRNA hydrolase. I. Properties of a mutant E. coli with temperature-sensitive peptidyl-tRNA hydrolase." Mol Gen Genet 121(4);307-24. PMID: 4571804
Ontiveros97: Ontiveros C, Valadez JG, Hernandez J, Guarneros G (1997). "Inhibition of Escherichia coli protein synthesis by abortive translation of phage lambda minigenes." J Mol Biol 269(2);167-75. PMID: 9191062
Oviedo04: Oviedo de Anda NA, Kameyama L, Galindo JM, Guarneros G, Hernandez-Sanchez J (2004). "Evidence of bar minigene expression and tRNA2Ile sequestration as peptidyl-tRNA2Ile during lambda bacteriophage development." J Bacteriol 186(16);5533-7. PMID: 15292158
Schmitt97: Schmitt E, Fromant M, Plateau P, Mechulam Y, Blanquet S (1997). "Crystallization and preliminary X-ray analysis of Escherichia coli peptidyl-tRNA hydrolase." Proteins 28(1);135-6. PMID: 9144799
Schmitt97a: Schmitt E, Mechulam Y, Fromant M, Plateau P, Blanquet S (1997). "Crystal structure at 1.2 A resolution and active site mapping of Escherichia coli peptidyl-tRNA hydrolase." EMBO J 16(15);4760-9. PMID: 9303320
Shiloach75: Shiloach J, Bauer S, de Groot N, Lapidot Y (1975). "The influence of the peptide chain length on the activity of peptidyl-tRNA hydrolase from E. coli." Nucleic Acids Res 2(10);1941-50. PMID: 1103091
VivancoDomingue06: Vivanco-Dominguez S, Cruz-Vera LR, Guarneros G (2006). "Excess of charged tRNALys maintains low levels of peptidyl-tRNA hydrolase in pth(Ts) mutants at a non-permissive temperature." Nucleic Acids Res 34(5);1564-70. PMID: 16540595
©2014 SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025-3493