|Gene:||fmt||Accession Numbers: EG11268 (EcoCyc), b3288, ECK3274|
Synonyms: ftm, yhdD
10-formyltetrahydrofolate:L-methionyl-tRNAfMet N-formyltransferase (Fmt) attaches a formyl group to the free amino group of methionyl-tRNAfMet [Kahn80, Guillon92]. There are two types of methionine-specific tRNAs in E. coli; the initiator tRNAmet is used in the initiation of translation, while a cytidine34 in tRNAmet is used during peptide chain elongation. The formylation of the methionine-charged initiator tRNA that is catalyzed by this enzyme is important in restricting the use of the methionylated initiator tRNA specifically for initiation, rather than chain elongation [Guillon93].
Substrate recognition determinants in Fmt [Schmitt96, Gite97, Ramesh97, Ramesh98, Schmitt98, Ramesh99, Li00] and specificity determinants within the tRNAfMet [Lee91, Guillon92a, Lee92a, Dyson93, Lee93, Wallis95, Li96a, Zuleeg00, Mayer02a] have been studied. Upon interaction with the acceptor stem of tRNAfMet, a previously unstructured insertion loop in the N-terminal domain of Fmt undergoes a structural change by induced fit [Ramesh99]. Overexpression of Fmt can rescue the activity of tRNA mutants that are normally poor substrates for Fmt [Mangroo95, Mayer03]. D-amino acid-charged tRNAfMet can act as a substrate for Fmt at low efficiency [Goto08].
Lysine residues in the linker region are important for enzymatic activity of Fmt, while the C-terminal domain is required for non-specific binding of tRNA [Gite00].
Fmt is monomeric [Kahn80, Schmitt96a]. Crystal structures of the enzyme alone [Schmitt96] and in a complex with formyl-methionyl-tRNAfMet [Schmitt98] have been solved at 2.0 Å and 2.8 Å resolution, respectively. An N-terminal Rossmann-fold domain is linked to a C-terminal domain resembling an OB fold which is able to bind tRNAfMet [Schmitt96].
Gene Citations: [Mazel94]
|Map Position: [3,432,236 -> 3,433,183] (73.98 centisomes)||Length: 948 bp / 315 aa|
Molecular Weight of Polypeptide: 34.168 kD (from nucleotide sequence), 32.0 kD (experimental) [Kahn80 ]
Unification Links: ASAP:ABE-0010781 , CGSC:33616 , DIP:DIP-9668N , EchoBASE:EB1247 , EcoGene:EG11268 , EcoliWiki:b3288 , ModBase:P23882 , OU-Microarray:b3288 , PortEco:fmt , PR:PRO_000022675 , Pride:P23882 , Protein Model Portal:P23882 , RefSeq:NP_417746 , RegulonDB:EG11268 , SMR:P23882 , String:511145.b3288 , UniProt:P23882
Relationship Links: InterPro:IN-FAMILY:IPR001555 , InterPro:IN-FAMILY:IPR002376 , InterPro:IN-FAMILY:IPR005793 , InterPro:IN-FAMILY:IPR005794 , InterPro:IN-FAMILY:IPR011034 , InterPro:IN-FAMILY:IPR015518 , Panther:IN-FAMILY:PTHR11138 , PDB:Structure:1FMT , PDB:Structure:2FMT , Pfam:IN-FAMILY:PF00551 , Pfam:IN-FAMILY:PF02911 , Prosite:IN-FAMILY:PS00373
In Paralogous Gene Group: 397 (3 members)
|Biological Process:||GO:0006413 - translational initiation
[Kahn80, GOA06, GOA01, GOA01a]
GO:0019988 - charged-tRNA amino acid modification [Kahn80]
GO:0006412 - translation [UniProtGOA11a, GOA06]
GO:0009058 - biosynthetic process [GOA01a]
GO:0032259 - methylation [GOA01a]
GO:0071951 - conversion of methionyl-tRNA to N-formyl-methionyl-tRNA [GOA01a]
|Molecular Function:||GO:0004479 - methionyl-tRNA formyltransferase activity
[GOA06, GOA01, GOA01a, Kahn80]
GO:0003824 - catalytic activity [GOA01a]
GO:0008168 - methyltransferase activity [GOA01a]
GO:0016740 - transferase activity [UniProtGOA11a]
GO:0016742 - hydroxymethyl-, formyl- and related transferase activity [GOA01a]
|Cellular Component:||GO:0005829 - cytosol
GO:0005737 - cytoplasm
|MultiFun Terms:||information transfer → RNA related → tRNA|
|Growth Medium||Growth?||T (°C)||O2||pH||Osm/L||Growth Observations|
|LB Lennox||No||37||Aerobic||7||No [Baba06, Comment 1]|
Enzymatic reaction of: 10-formyltetrahydrofolate:L-methionyl-tRNAfMet N-formyltransferase
Synonyms: MTF, methionyl-tRNA transformylase
EC Number: 18.104.22.168
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.
Partial purification of the enzyme was first reported from E. coli B [Dickerman67].
The enzyme is specific for mehtionyl-initiator tRNAmet; it does not formylate methionyl-a cytidine34 in tRNAmet. The enzyme is able to bind uncharged tRNAfMet, but it has higher affinity for the charged methionyl-tRNAfMet [Kahn80].
|Feature Class||Location||Common Name||Citations||Comment|
|Protein-Segment||2 -> 189|
|Chain||2 -> 315|
|Amino-Acid-Sites-That-Bind||43||initiator tRNA interaction determinant|
|Protein-Segment||113 -> 116|
|Protein-Segment||210 -> 315|
10/20/97 Gene b3288 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG11268; 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
Dickerman67: Dickerman HW, Steers E, Redfield BG, Weissbach H (1967). "Methionyl soluble ribonucleic acid transformylase. I. Purification and partial characterization." J Biol Chem 242(7);1522-5. PMID: 5337045
Gite00: Gite S, Li Y, Ramesh V, RajBhandary UL (2000). "Escherichia coli methionyl-tRNA formyltransferase: role of amino acids conserved in the linker region and in the C-terminal domain on the specific recognition of the initiator tRNA." Biochemistry 39(9);2218-26. PMID: 10694387
Gite97: Gite S, RajBhandary UL (1997). "Lysine 207 as the site of cross-linking between the 3'-end of Escherichia coli initiator tRNA and methionyl-tRNA formyltransferase." J Biol Chem 272(8);5305-12. PMID: 9030604
Guillon92: Guillon JM, Mechulam Y, Schmitter JM, Blanquet S, Fayat G (1992). "Disruption of the gene for Met-tRNA(fMet) formyltransferase severely impairs growth of Escherichia coli." J Bacteriol 174(13);4294-301. PMID: 1624424
Guillon92a: Guillon JM, Meinnel T, Mechulam Y, Lazennec C, Blanquet S, Fayat G (1992). "Nucleotides of tRNA governing the specificity of Escherichia coli methionyl-tRNA(fMet) formyltransferase." J Mol Biol 224(2);359-67. PMID: 1373194
Guillon93: Guillon JM, Mechulam Y, Blanquet S, Fayat G (1993). "Importance of formylability and anticodon stem sequence to give a tRNA(Met) an initiator identity in Escherichia coli." J Bacteriol 175(14);4507-14. PMID: 8331078
Kahn80: Kahn D, Fromant M, Fayat G, Dessen P, Blanquet S (1980). "Methionyl-transfer-RNA transformylase from Escherichia coli. Purification and characterisation." Eur J Biochem 105(3);489-97. PMID: 6989606
Lee91: Lee CP, Seong BL, RajBhandary UL (1991). "Structural and sequence elements important for recognition of Escherichia coli formylmethionine tRNA by methionyl-tRNA transformylase are clustered in the acceptor stem." J Biol Chem 266(27);18012-7. PMID: 1917939
Lee92a: Lee CP, Dyson MR, Mandal N, Varshney U, Bahramian B, RajBhandary UL (1992). "Striking effects of coupling mutations in the acceptor stem on recognition of tRNAs by Escherichia coli Met-tRNA synthetase and Met-tRNA transformylase." Proc Natl Acad Sci U S A 89(19);9262-6. PMID: 1409632
Lee93: Lee CP, Mandal N, Dyson MR, RajBhandary UL (1993). "The discriminator base influences tRNA structure at the end of the acceptor stem and possibly its interaction with proteins." Proc Natl Acad Sci U S A 90(15);7149-52. PMID: 8346229
Li00: Li Y, Ramesh V, Mangroo D, Taneja C, RajBhandary UL (2000). "Suppressor mutations in Escherichia coli methionyl-tRNA formyltransferase that compensate for the formylation defect of a mutant tRNA aminoacylated with lysine." Biochemistry 39(27);8039-46. PMID: 10891086
Li96a: Li S, Kumar NV, Varshney U, RajBhandary UL (1996). "Important role of the amino acid attached to tRNA in formylation and in initiation of protein synthesis in Escherichia coli." J Biol Chem 271(2);1022-8. PMID: 8557626
LopezCampistrou05: Lopez-Campistrous A, Semchuk P, Burke L, Palmer-Stone T, Brokx SJ, Broderick G, Bottorff D, Bolch S, Weiner JH, Ellison MJ (2005). "Localization, annotation, and comparison of the Escherichia coli K-12 proteome under two states of growth." Mol Cell Proteomics 4(8);1205-9. PMID: 15911532
Mangroo95: Mangroo D, RajBhandary UL (1995). "Mutants of Escherichia coli initiator tRNA defective in initiation. Effects of overproduction of methionyl-tRNA transformylase and the initiation factors IF2 and IF3." J Biol Chem 270(20);12203-9. PMID: 7538134
Mangroo95a: Mangroo D, Wu XQ, RajBhandary UL (1995). "Escherichia coli initiator tRNA: structure-function relationships and interactions with the translational machinery." Biochem Cell Biol 73(11-12);1023-31. PMID: 8722017
Mayer02a: Mayer C, RajBhandary UL (2002). "Conformational change of Escherichia coli initiator methionyl-tRNA(fMet) upon binding to methionyl-tRNA formyl transferase." Nucleic Acids Res 30(13);2844-50. PMID: 12087168
Mayer03: Mayer C, Kohrer C, Kenny E, Prusko C, RajBhandary UL (2003). "Anticodon sequence mutants of Escherichia coli initiator tRNA: effects of overproduction of aminoacyl-tRNA synthetases, methionyl-tRNA formyltransferase, and initiation factor 2 on activity in initiation." Biochemistry 42(17);4787-99. PMID: 12718519
Meinnel93: Meinnel T, Guillon JM, Mechulam Y, Blanquet S (1993). "The Escherichia coli fmt gene, encoding methionyl-tRNA(fMet) formyltransferase, escapes metabolic control." J Bacteriol 175(4);993-1000. PMID: 8432722
Ramesh97: Ramesh V, Gite S, Li Y, RajBhandary UL (1997). "Suppressor mutations in Escherichia coli methionyl-tRNA formyltransferase: role of a 16-amino acid insertion module in initiator tRNA recognition." Proc Natl Acad Sci U S A 94(25);13524-9. PMID: 9391059
Ramesh98: Ramesh V, Gite S, RajBhandary UL (1998). "Functional interaction of an arginine conserved in the sixteen amino acid insertion module of Escherichia coli methionyl-tRNA formyltransferase with determinants for formylation in the initiator tRNA." Biochemistry 37(45);15925-32. PMID: 9843398
Ramesh99: Ramesh V, Mayer C, Dyson MR, Gite S, RajBhandary UL (1999). "Induced fit of a peptide loop of methionyl-tRNA formyltransferase triggered by the initiator tRNA substrate." Proc Natl Acad Sci U S A 96(3);875-80. PMID: 9927661
Schmitt96: Schmitt E, Blanquet S, Mechulam Y (1996). "Structure of crystalline Escherichia coli methionyl-tRNA(f)Met formyltransferase: comparison with glycinamide ribonucleotide formyltransferase." EMBO J 15(17);4749-58. PMID: 8887566
Schmitt96a: Schmitt E, Mechulam Y, Ruff M, Mitschler A, Moras D, Blanquet S (1996). "Crystallization and preliminary X-ray analysis of Escherichia coli methionyl-tRNA(fMet) formyltransferase." Proteins 25(1);139-41. PMID: 8727328
Schmitt96b: Schmitt E, Guillon JM, Meinnel T, Mechulam Y, Dardel F, Blanquet S (1996). "Molecular recognition governing the initiation of translation in Escherichia coli. A review." Biochimie 78(7);543-54. PMID: 8955898
Schmitt98: Schmitt E, Panvert M, Blanquet S, Mechulam Y (1998). "Crystal structure of methionyl-tRNAfMet transformylase complexed with the initiator formyl-methionyl-tRNAfMet." EMBO J 17(23);6819-26. PMID: 9843487
Wallis95: Wallis NG, Dardel F, Blanquet S (1995). "Heteronuclear NMR studies of the interactions of 15N-labeled methionine-specific transfer RNAs with methionyl-tRNA transformylase." Biochemistry 34(23);7668-77. PMID: 7779813
Zuleeg00: Zuleeg T, Vogtherr M, Schubel H, Limmer S (2000). "The C-A mismatch base pair and the single-strand terminus in the E. coli initiator tRNA(fMet) acceptor stem adopt unusual conformations." FEBS Lett 472(2-3);247-53. PMID: 10788620
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