>gnl|CDD|29495 cd00397, DNA_BRE_C, DNA breaking-rejoining enzymes, C-terminal catalytic domain. The DNA breaking-rejoining enzyme superfamily includes type IB topoisomerases and tyrosine recombinases that share the same fold in their catalytic domain containing six conserved active site residues. The best-studied members of this diverse superfamily include human topoisomerase I, the bacteriophage lambda integrase, the bacteriophage P1 Cre recombinase, the yeast Flp recombinase and the bacterial XerD/C recombinases. Their overall reaction mechanism is essentially identical and involves cleavage of a single strand of a DNA duplex by nucleophilic attack of a conserved tyrosine to give a 3' phosphotyrosyl protein-DNA adduct. In the second rejoining step, a terminal 5' hydroxyl attacks the covalent adduct to release the enzyme and generate duplex DNA. The enzymes differ in that topoisomerases cleave and then rejoin the same 5' and 3' termini, whereas a site-specific recombinase transfers a 5' hydroxyl generated by recombinase cleavage to a new 3' phosphate partner located in a different duplex region. Many DNA breaking-rejoining enzymes also have N-terminal domains, which show little sequence or structure similarity.. Length = 164

 Score =  111 bits (278), Expect = 3e-25
 Identities = 64/154 (41%), Positives = 85/154 (55%), Gaps = 5/154 (3%)

Query: 125 KRVRIFLLIELLYATGMRVSELVTLSAHTLNLTERTM-IIQGKGNKERLVILSPSALHAL 183
              R++L + LL ATG+R+SEL  L    ++L +R + I   K  KER V LS  AL  L
Sbjct: 13  TPERLYLALLLLLATGLRISELCALRWSDIDLDKRVIHITGTKTKKERTVPLSEEALKLL 72

Query: 184 QMYKKTCSSMKMTGNDLWLFPSSTKT--GHLSRQVFARDLKALAARAGIQKKNISPHIIR 241
           + Y K        G++ +LFPS        LSR+   R  KA   RAGI K+ ++PH +R
Sbjct: 73  KEYLKKRRPAN--GDEEYLFPSRRGGPAATLSRRNVKRIFKAAGRRAGIDKEGLTPHSLR 130

Query: 242 HAFASHLLEGGADLRTIQILLGHTDISTTQIYTH 275
           H FAS LL  G DL  +Q LLGH+ I+ T  Y H
Sbjct: 131 HTFASALLNAGLDLEAVQDLLGHSSIAMTMRYAH 164