Escherichia coli Migula (bacterium) K-12 MG1655 [ECO]

FULL NAME: DNA-3-methyladenine glycosylase 2


DESCRIPTION:
Hydrolysis of the deoxyribose N-glycosidic bond to excise 3-methyladenine, 3-methylguanine, 7-methylguanine, O2-methylthymine, and O2-methylcytosine from the damaged DNA polymer formed by alkylation lesions.
AlkA is monofunctional DNA-N-glycosylase.
Hydrolysis of the deoxyribose N-glycosidic bond to excise 3-methyladenine, 3-methylguanine, 7-methylguanine, O2-methylthymine, O2-methylcytosine, 7-(2-chloroethyl)guanine, 7-(2-hydroxyethyl)guanine, 7-(2-ethoxyethyl)guanine, 1,N6-ethenoadenine, hypoxanthine, adenine, guanine, thymine and cytosine from damaged and normal DNA. Repairs also 5-formyluracil, a major thymine lesion produced by reactive oxygen radicals and photosensitized oxidation. The sulfur mustard treated DNA as substrate enzyme releases 7-hydroxyethylthioethyl guanine and 3-hydroxyethylthioethyl adenine, can also release carboxyethylate purines from DNA.

3-ethenoguanine and 8-oxoguanine are not released. Also 5-hydroxymethyluracil, major thymine methyl oxidation product, is not a substrate.

STRUCTURE SIMILARITY:
Belongs to the alkylbase DNA glycosidase AlkA family.


CATALYTIC ACTIVITY:
Hydrolysis of alkylated DNA, releasing 3-methyladenine, 3-methylguanine, 7-methylguanine and 7-methyladenine.


PROTEIN TYPE(S):
DNA N-glycosylase


RELATED PATHWAY(S):
base excision repair (BER)


RELATED DAMAGE:
7-methyl A (7meA)
N7-methyl G (7meG)
N2,3-etheno-G (N2,3-εG)
1,N6-etheno-A (1εA)
8-methyl G (8meG)
O2-methyl T (O2meT)
1,N6-ethano A (EA)
O2-methyl C (O2meC)
5-hydroxymethyl U (5-OH-me-U)
3-methyl A (3-meA) in ssDNA
5-formyl dU (5-foU)
1,N6-etheno-A in (1εA) dsDNA
3,N4-ethano-C (EC)
3-methyl A (3meA)
N3-methyl G (3meG)


Amino acids sequence

        10         20         30         40         50         60
MYTLNWQPPY DWSWMLGFLA ARAVSSVETV ADSYYARSLA VGEYRGVVTA IPDIARHTLH
        70         80         90        100        110        120
INLSAGLEPV AAECLAKMSR LFDLQCNPQI VNGALGRLGA ARPGLRLPGC VDAFEQGVRA
       130        140        150        160        170        180
ILGQLVSVAM AAKLTARVAQ LYGERLDDFP EYICFPTPQR LAAADPQALK ALGMPLKRAE
       190        200        210        220        230        240
ALIHLANAAL EGTLPMTIPG DVEQAMKTLQ TFPGIGRWTA NYFALRGWQA KDVFLPDDYL
       250        260        270        280
IKQRFPGMTP AQIRRYAERW KPWRSYALLH IWYTEGWQPD EA 

Encoded by alkA gene


OTHER NAME(S):
aidA
ECK2062
JW2053


DESCRIPTION:
The alk gene product is known as 3-methyladenine-DNA glycosylase II and is induced by exposure to alkylating agents as part of the cell's adaptive response to damage caused by alkylation. [More information is available at EcoCyc: EG11222].


Nucleic acid sequence

        10         20         30         40         50         60
atgtataccc tgaactggca gccgccgtat gactggtcgt ggatgttggg atttctcgcc
        70         80         90        100        110        120
gcccgtgcgg tgagcagtgt ggaaacggtc gcggacagtt attatgcccg tagtctggcg
       130        140        150        160        170        180
gtgggcgaat atcgcggcgt ggtgactgct attccggata tagcccgcca tactctgcac
       190        200        210        220        230        240
ataaatttaa gtgcaggttt agaacctgtt gccgcagagt gtctggcgaa aatgagccgc
       250        260        270        280        290        300
ctgtttgatc tgcaatgtaa cccacaaatt gttaacggtg cgttgggcag gttaggcgcg
       310        320        330        340        350        360
gcgcggcccg gattgcgttt acccggctgt gttgatgctt ttgagcaggg cgtgcgggcg
       370        380        390        400        410        420
attttaggcc aactggtgag cgtggcgatg gcggcaaaat tgaccgccag agtggcacag
       430        440        450        460        470        480
ctttatggcg aacggctgga tgattttccg gagtatatct gcttcccgac gcctcagcgg
       490        500        510        520        530        540
ctggcagcag cagacccgca ggcattaaaa gcgttaggta tgccgttgaa acgggcagag
       550        560        570        580        590        600
gcgctgattc atctggcaaa tgcggcgctg gagggcacct taccaatgac aataccgggc
       610        620        630        640        650        660
gatgtggagc aggcgatgaa aacgctgcaa acttttccgg gtatcgggcg ctggacggcg
       670        680        690        700        710        720
aattattttg ctttgcgtgg ctggcaggcg aaagatgttt tcctgccgga tgattatctg
       730        740        750        760        770        780
attaaacagc gatttccggg aatgacaccg gcgcaaatcc gccgttatgc cgagcgctgg
       790        800        810        820        830        840
aagccctggc gttcttatgc gctgttgcat atctggtata cggaaggctg gcaaccagac

gaagcatga     

Last modification date: Oct. 2, 2011