Reviewed, UniProtKB/Swiss-Prot P09358 (MTD22_STRPN)

Names and origin

Protein names

Recommended name:
    Modification methylase DpnIIB
      Short name=M.DpnIIB
    EC=2.1.1.72
Alternative name(s):
    Adenine-specific methyltransferase DpnIIB
    M.DpnII 2

Gene names

Name:

dpnA

Organism

Streptococcus pneumoniae

Taxonomic identifier

1313 [NCBI]

Taxonomic lineage

Bacteria › Firmicutes › Lactobacillales › Streptococcaceae › Streptococcus

Protein attributes

Sequence length	268 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Essential for establishment of a previously unmethylated plasmid transformed into the cell as single stranded DNA. Recognizes the single- or double-stranded sequence GATC, causes specific methylation on A-2 on one or both strands (respectively), and protects the DNA from cleavage by the DpnII endonuclease.
Catalytic activity	S-adenosyl-L-methionine + DNA adenine = S-adenosyl-L-homocysteine + DNA 6-methylaminopurine.
Subunit structure	Homodimer.
Miscellaneous	The DpnII restriction system has two different methylases.
Sequence similarities	Belongs to the N(4)/N(6)-methyltransferase family.

Ontologies

Keywords
Biological process	Restriction system
Coding sequence diversity	Alternative initiation
Ligand	S-adenosyl-L-methionine
Molecular function	Methyltransferase Transferase
Technical term	Direct protein sequencing
Gene Ontology (GO)
None. [Check GOA]

Alternative products

This entry describes 2 isoforms produced by alternative initiation. [Align] [Select]

Isoform 1 (identifier: P09358-1)

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

Isoform 2 (identifier: P09358-2)

The sequence of this isoform differs from the canonical sequence as follows:
     1-12: Missing.

Notes: Produced in response to the induction of competence for genetic transformation.

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view
Molecule processing
	Chain	1 – 268	268	Modification methylase DpnIIB
Natural variations
	Alternative sequence	1 – 12	12	Missing in isoform 2.

Sequences

	Sequence		Length	Mass (Da)
	Isoform 1 [UniParc]. Last modified July 1, 1989. Version 1. Checksum: DD039104E3A915FC	FASTA	268	30,922
	10 20 30 40 50 60 MKNNEYKYGG VLMTKPYYNK NKMILVHSDT FKFLSKMKPE SMDMIFADPP YFLSNGGISN 70 80 90 100 110 120 SGGQVVSVDK GDWDKISSFE EKHEFNRKWI RLAKEVLKPN GTVWISGSLH NIYSVGMALE 130 140 150 160 170 180 QEGFKILNNI TWQKTNPAPN LSCRYFTHST ETILWARKND KKARHYYNYD LMKELNDGKQ 190 200 210 220 230 240 MKDVWTGSLT KKVEKWAGKH PTQKPEYLLE RIILASTKEG DYILDPFVGS GTTGVVAKRL 250 260 GRRFIGIDAE KEYLKIARKR LEAENETN
	Isoform 2 [UniParc]. Checksum: 6CEC667BE4907954		256	29,525
	10 20 30 40 50 60 MTKPYYNKNK MILVHSDTFK FLSKMKPESM DMIFADPPYF LSNGGISNSG GQVVSVDKGD 70 80 90 100 110 120 WDKISSFEEK HEFNRKWIRL AKEVLKPNGT VWISGSLHNI YSVGMALEQE GFKILNNITW 130 140 150 160 170 180 QKTNPAPNLS CRYFTHSTET ILWARKNDKK ARHYYNYDLM KELNDGKQMK DVWTGSLTKK 190 200 210 220 230 240 VEKWAGKHPT QKPEYLLERI ILASTKEGDY ILDPFVGSGT TGVVAKRLGR RFIGIDAEKE 250 YLKIARKRLE AENETN

References

[1]	"Genetic basis of the complementary DpnI and DpnII restriction systems of S. pneumoniae: an intercellular cassette mechanism." Lacks S.A., Mannarelli B.M., Springhorn S.S., Greenberg B. Cell 46:993-1000(1986) [PubMed: 3019562] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] (ISOFORM 2).
[2]	"Regulation of competence for genetic transformation in Streptococcus pneumoniae: expression of dpnA, a late competence gene encoding a DNA methyltransferase of the DpnII restriction system." Lacks S.A., Ayalew S., de la Campa A.G., Greenberg B. Mol. Microbiol. 35:1089-1098(2000) [PubMed: 10712690] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] (ISOFORMS 1 AND 2), SEQUENCE REVISION TO N-TERMINUS, ALTERNATIVE INITIATION.
[3]	"Proteins encoded by the DpnII restriction gene cassette. Two methylases and an endonuclease." de la Campa A.G., Purushottam K., Springhorn S.S., Lacks S.A. J. Mol. Biol. 196:457-469(1987) [PubMed: 2824782] [Abstract] Cited for: PROTEIN SEQUENCE OF 1-13 (ISOFORM 1), FUNCTION.

Cross-references

Sequence databases
EMBLGenBankDDBJ	M14339 Genomic DNA. Translation: AAA88581.2.
PIR	A24372.
3D structure databases
HSSP	HSSP built from PDB template 1G60 based on UniProtKB P23192.
ModBase	Search...
Protein family/group databases
REBASE	3637. M2.DpnII.
Family and domain databases
InterPro	IPR002295. D21N6_MeTrfase. IPR001091. MeTrfase_CN4. IPR002941. N6/N4_Mtase. IPR002052. N6_adenine_Mtase_CS. [Graphical view]
Pfam	PF01555. N6_N4_Mtase. 1 hit. [Graphical view]
PRINTS	PR00506. D21N6MTFRASE. PR00508. S21N4MTFRASE.
PROSITE	PS00092. N6_MTASE. 1 hit. [Graphical view]
ProDom	P09358. [Graphical view] [Entries sharing at least one domain]
BLOCKS	Search...
Other Resources
LinkHub	P09358.
ProtoNet	Search...

Entry information

Entry name

MTD22_STRPN

Accession

Primary (citable) accession number: P09358

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 1, 1989
Last sequence update:	July 1, 1989
Last modified:	September 2, 2008
This is version 71 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

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