Protein
ATP-dependent helicase/nuclease subunit A
Organism
Lactococcus lactis subsp. cremoris (strain MG1363)
Function
The heterodimer acts as both an ATP-dependent DNA helicase and an ATP-dependent, dual-direction single-stranded exonuclease. Recognizes the L.lactis chi site (5'-GCGCGTG-3'), which stimulates homologous recombination. The AddA nuclease domain is required for chi fragment generation; this subunit has 3'->5' exonuclease activity and probably also performs the helicase function.
Similarity
Belongs to the helicase family. AddA subfamily.
Sequence
MSEVKLTPEQNEAIHSSGKNILVSASAGSGKTFVMAQRIVEKVKQGIEIDRLFISTFTKKAASELRMRLERDLKKARQESSDDEEAHRLTLALQNLSNADIGTMDSFTQKLTKANFNRVNIDPNFRILADQTESDLIRQEVFEQLVESYLSADESLNISKDKFEKLIKNFSKDRNILGFQKVVYTIYRFASATENPISWLENQFLKGFETYKSLTDLSEDFTVNVKENLLTFFELLENSLTNGVIAKKGAGRDKANLILDNKNELLEAISKKDFVTCTALFLSIDTDIRVGSSKDEALSALKKDFSAQKQDLVGSKSKPGELRKFVDKIKHGQLIEKYQNQAFEIASDLQKFIIDFYKTYLERKKNENAFEYSDIAHFAIEILEENPDIRENLREHYDEIMIDEYQDTSHTQERMLELLSNGHNLFMVGDIKQSIYGFRLADPGLFLEKYKSYDQAENPNQLIRLKENFRSRGEVLNFTNDIFKHLMDEKLGEMTYGKEEALVQGNISDYPVEAEKDFYPELLLYKENTSEEEIEDSEVKISDGEIKGAAQEIKKLIEYGVEPKDIAILVRSKSNNNKIEDILLSYDIPVVLDEGRVDFLKSMEVLIMLDVLRAIDNPLYDLSLVAMLRSPLFGFNEDELTRISVQGSRDLRFWDKILLSLKKEGKNPELINLSLEQKLKAFNQKFTEWRKLVNKIPIHRLLWKIYTETYYFDYVGALKNGEMRQANLQALSVRAESYESSGYKGLFKFVRLINKFMEQNNDLASVNIKLPQNAVRVMTFHKSKGLEFDYVFLMNLQSRFNDRDLKEDVILSREHGLGMKYIADLKAEPDVITDFPYALVKMETFPYMVNKDLKQRAALSEEMRVLYVAFTRAKKKLYLVGKIKDTDKKAGLELYDAATLEGKILSDKFRNSSRGFQHWILALQNATKLPMKLNVYTKDELETEKLEFTSQPDFKKLVEESEKFDNIMSFSDEIKEAQKIMNYQYPHQAATELSSIQTPSQVKKRSYEKQLQVGEVQPVSEFVRVKNLDFSDFGPKKITAAEMGSATHSFMQYADFSQADLFSFQATLDEMGFDEKIKNQIDITKILTLFDTEFGQFLSENVDKTVKEAPFSMLRTDEFAKEQYIVRGICDGFVKLADKIILFDYKTDRFTNVSAISEIKERYKDQMNLYSEALQKAYHVNQIDKYLILLGGPRKVFVEKIDD