Reviewed, UniProtKB/Swiss-Prot P14385 (MTTA_THEAQ)

Names and origin

Protein names

Recommended name:
    Modification methylase TaqI
      Short name=M.TaqI
    EC=2.1.1.72
Alternative name(s):
    Adenine-specific methyltransferase TaqI

Gene names

Name:

taqIM

Organism

Thermus aquaticus

Taxonomic identifier

271 [NCBI]

Taxonomic lineage

Bacteria › Deinococcus-Thermus › Deinococci › Thermales › Thermaceae › Thermus

Protein attributes

Sequence length	421 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	This methylase recognizes the double-stranded sequence TCGA, causes specific methylation on A-4 on both strands and protects the DNA from cleavage by the TaqI endonuclease.
Catalytic activity	S-adenosyl-L-methionine + DNA adenine = S-adenosyl-L-homocysteine + DNA 6-methylaminopurine.
Sequence similarities	Belongs to the N(4)/N(6)-methyltransferase family.
Biophysicochemical properties	Kinetic parameters: KM=0.6 µM for DNA Ref.3 KM=3.7 µM for S-adenosylmethionine

Ontologies

Keywords
Biological process	Restriction system
Ligand	S-adenosyl-L-methionine
Molecular function	Methyltransferase Transferase
Technical term	3D-structure
Gene Ontology (GO)
Biological process	DNA restriction-modification system Inferred from electronic annotation. Source: UniProtKB-KW methylation Inferred from electronic annotation. Source: InterPro
Molecular function	nucleic acid binding Inferred from electronic annotation. Source: InterPro site-specific DNA-methyltransferase (adenine-specific) activity Inferred from electronic annotation. Source: EC
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Chain

1 – 421

421

Modification methylase TaqI

PRO_0000087980

Experimental info

Mutagenesis

108

1

Y → A or G: Drastically reduces enzymatic activity; KM for both DNA and s-adenosylmethionine is not significantly changed. Ref.3

Mutagenesis

108

1

Y → F or W: Essentially wild-type activity. Ref.3

Mutagenesis

196

1

F → A: Drastically reduces enzymatic activity; KM for both DNA and s-adenosylmethionine is not significantly changed. Ref.3

Mutagenesis

196

1

F → W: Essentially wild-type activity. Ref.3

Sequence conflict

13

1

S → A in CAA68551. Ref.1

Sequence conflict

64

1

A → G in AAA27506. Ref.1

Secondary structure

1

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

421

Helix Strand Turn

Details...

Helix

25 – 32

8

Beta strand

42 – 46

5

Helix

52 – 61

10

Beta strand

65 – 72

8

Turn

74 – 76

3

Beta strand

83 – 88

6

Helix

90 – 92

3

Beta strand

99 – 104

6

Turn

114 – 116

3

Helix

123 – 132

10

Helix

142 – 153

12

Beta strand

154 – 166

13

Helix

167 – 169

3

Helix

172 – 174

3

Helix

175 – 184

10

Beta strand

185 – 194

10

Beta strand

203 – 212

10

Beta strand

215 – 223

9

Beta strand

226 – 235

10

Helix

248 – 254

7

Beta strand

257 – 259

3

Helix

260 – 263

4

Beta strand

264 – 268

5

Helix

272 – 277

6

Beta strand

282 – 284

3

Beta strand

289 – 291

3

Helix

295 – 297

3

Beta strand

309 – 311

3

Beta strand

313 – 315

3

Helix

316 – 321

6

Helix

324 – 327

4

Beta strand

330 – 333

4

Beta strand

335 – 340

6

Beta strand

343 – 348

6

Beta strand

352 – 360

9

Beta strand

364 – 366

3

Helix

368 – 375

8

Helix

378 – 388

11

Beta strand

391 – 394

4

Helix

397 – 401

5

Turn

407 – 409

3

Beta strand

410 – 412

3

Sequences

	Sequence		Length	Mass (Da)
	P14385-1 [UniParc]. Last modified October 17, 2006. Version 3. Checksum: 21C62B53C43DB7FF	FASTA	421	47,862
	10 20 30 40 50 60 MGLPPLLSLP SNSAPRSLGR VETPPEVVDF MVSLAEAPRG GRVLEPACAH GPFLRAFREA 70 80 90 100 110 120 HGTAYRFVGV EIDPKALDLP PWAEGILADF LLWEPGEAFD LILGNPPYGI VGEASKYPIH 130 140 150 160 170 180 VFKAVKDLYK KAFSTWKGKY NLYGAFLEKA VRLLKPGGVL VFVVPATWLV LEDFALLREF 190 200 210 220 230 240 LAREGKTSVY YLGEVFPQKK VSAVVIRFQK SGKGLSLWDT QESESGFTPI LWAEYPHWEG 250 260 270 280 290 300 EIIRFETEET RKLEISGMPL GDLFHIRFAA RSPEFKKHPA VRKEPGPGLV PVLTGRNLKP 310 320 330 340 350 360 GWVDYEKNHS GLWMPKERAK ELRDFYATPH LVVAHTKGTR VVAAWDERAY PWREEFHLLP 370 380 390 400 410 420 KEGVRLDPSS LVQWLNSEAM QKHVRTLYRD FVPHLTLRML ERLPVRREYG FHTSPESARN F

References

[1]	"Cloning, sequencing and expression of the Taq I restriction-modification system." Slatko B.E., Benner J.S., Moran L.S., Jager-Quinton T., Simcox T.G., van Cott E.M., Wilson G.G. Nucleic Acids Res. 15:9781-9796(1987) [PubMed: 2827113] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: YT1.
[2]	"The corrected nucleotide sequences of the TaqI restriction and modification enzymes reveal a thirteen-codon overlap." Barany F., Slatko B., Danzitz M., Cowburn D., Schildkraut I., Wilson G.G. Gene 112:91-95(1992) [PubMed: 1551602] [Abstract] Cited for: SEQUENCE REVISION. Strain: YT1.
[3]	"Functional roles of the conserved aromatic amino acid residues at position 108 (motif IV) and position 196 (motif VIII) in base flipping and catalysis by the N6-adenine DNA methyltransferase from Thermus aquaticus." Pues H., Bleimling N., Holz B., Wolcke J., Weinhold E. Biochemistry 38:1426-1434(1999) [PubMed: 9931007] [Abstract] Cited for: MUTAGENESIS OF TYR-108 AND PHE-196, KINETIC PROPERTIES.
[4]	"Three-dimensional structure of the adenine-specific DNA methyltransferase M.Taq I in complex with the cofactor S-adenosylmethionine." Labahn J., Granzin J., Schluckebier G., Robinson D.P., Jack W.E., Schildkraut I., Saenger W. Proc. Natl. Acad. Sci. U.S.A. 91:10957-10961(1994) [PubMed: 7971991] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.4 ANGSTROMS) IN COMPLEX WITH S-ADENOSYLMETHIONINE.
[5]	"Differential binding of S-adenosylmethionine S-adenosylhomocysteine and sinefungin to the adenine-specific DNA methyltransferase M.TaqI." Schluckebier G., Kozak M., Bleimling N., Weinhold E., Saenger W. J. Mol. Biol. 265:56-67(1997) [PubMed: 8995524] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.6 ANGSTROMS) IN COMPLEX WITH S-ADENOSYLHOMOCYSTEINE AND SINEFUNGIN, A REINTERPRETATION IN COMPLEX WITH S-ADENOSYLMETHIONINE.
[6]	"Structure of the N6-adenine DNA methyltransferase M.TaqI in complex with DNA and a cofactor analog." Goedecke K., Pignot M., Goody R.S., Scheidig A.J., Weinhold E. Nat. Struct. Biol. 8:121-125(2001) [PubMed: 11175899] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS) OF 21-413 IN COMPLEX WITH DNA AND A COFACTOR ANALOG, DISCUSSION OF ENZYME MECHANISM.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBLGenBankDDBJ

Y00499 Genomic DNA. Translation: CAA68551.1. Sequence problems.
M76681 Genomic DNA. Translation: AAA27506.1.

PIR

JN0257.

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1AQI	X-ray	2.60	A/B	1-421	[»]
1AQJ	X-ray	2.60	A/B	1-421	[»]
1G38	X-ray	2.00	A/D	21-413	[»]
2ADM	X-ray	2.60	A/B	1-421	[»]
2IBS	X-ray	2.40	A/D	1-421	[»]
2IBT	X-ray	1.70	A/D	1-421	[»]
2IH2	X-ray	1.61	A/D	1-421	[»]
2IH4	X-ray	2.10	A/D	1-421	[»]
2IH5	X-ray	1.80	A	1-421	[»]
2JG3	X-ray	1.90	A/D	1-421	[»]
2NP6	X-ray	2.10	A/D	1-421	[»]
2NP7	X-ray	1.90	A	1-421	[»]

ModBase

Search...

Enzyme and pathway databases

BRENDA

2.1.1.72. 118.

Family and domain databases

InterPro

IPR002052. DNA_methylase_N6_adenine_CS.
IPR002296. N12N6_MeTrfase.
[Graphical view]

PRINTS

PR00507. N12N6MTFRASE.

PROSITE

PS00092. N6_MTASE. 1 hit.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

MTTA_THEAQ

Accession

Primary (citable) accession number: P14385

Entry history

Integrated into UniProtKB/Swiss-Prot:	January 1, 1990
Last sequence update:	October 17, 2006
Last modified:	September 22, 2009
This is version 75 of the entry and version 3 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HAMAP (High-quality Automated and Manual Annotation of microbial Proteomes)