ID   LTRB_LACLC              Reviewed;         563 AA.
AC   Q48722;
DT   27-MAR-2002, integrated into UniProtKB/Swiss-Prot.
DT   04-DEC-2007, sequence version 2.
DT   03-AUG-2022, entry version 59.
DE   RecName: Full=Group II intron-interrupted relaxase LtrB;
DE   AltName: Full=Conjugative nickase;
GN   Name=ltrBE1;
GN   and
GN   Name=ltrBE2;
OS   Lactococcus lactis subsp. cremoris (Streptococcus cremoris).
OG   Plasmid pRS01.
OC   Bacteria; Firmicutes; Bacilli; Lactobacillales; Streptococcaceae;
OC   Lactococcus.
OX   NCBI_TaxID=1359;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=NCDO 763 / ML3;
RX   PubMed=8655550; DOI=10.1128/jb.178.12.3531-3538.1996;
RA   Mills D.A., McKay L.L., Dunny G.M.;
RT   "Splicing of a group II intron involved in the conjugative transfer of
RT   pRS01 in Lactococci.";
RL   J. Bacteriol. 178:3531-3538(1996).
RN   [2]
RP   FUNCTION.
RX   PubMed=10532373; DOI=10.1023/a:1002085605743;
RA   Dunny G.M., McKay L.L.;
RT   "Group II introns and expression of conjugative transfer functions in
RT   lactic acid bacteria.";
RL   Antonie Van Leeuwenhoek 76:77-88(1999).
CC   -!- FUNCTION: Mediates initition of conjugal transfer of plasmid pRS01
CC       possibly by introducing a single-stranded nick at the potential origin
CC       of transfer, to initiate single strand transfer from donor to
CC       recipient. {ECO:0000269|PubMed:10532373}.
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000305};
CC       Name=Mn(2+); Xref=ChEBI:CHEBI:29035; Evidence={ECO:0000305};
CC   -!- MISCELLANEOUS: The gene coding for this protein is interrupted by a
CC       group II intron, Ll.LtrB. Splicing of the intervening intron is
CC       necessary for proper protein activity and, therefore, conjugative
CC       transfer of pRS01, as the splicing event brings together the two
CC       conserved histidine residues proposed to function as ligands for the
CC       metal ion cofactor.
CC   -!- SIMILARITY: Belongs to the mobilization (MOB) protein type 1 family.
CC       {ECO:0000305}.
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DR   EMBL; U50902; AAB06502.2; -; Genomic_DNA.
DR   AlphaFoldDB; Q48722; -.
DR   SMR; Q48722; -.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   InterPro; IPR005094; Endonuclease_MobA/VirD2.
DR   Pfam; PF03432; Relaxase; 1.
PE   3: Inferred from homology;
KW   Conjugation; Magnesium; Manganese; Metal-binding; Mobility protein;
KW   Plasmid.
FT   CHAIN           1..563
FT                   /note="Group II intron-interrupted relaxase LtrB"
FT                   /id="PRO_0000084514"
FT   ACT_SITE        44
FT                   /evidence="ECO:0000255"
FT   BINDING         159
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255"
FT   BINDING         161
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   563 AA;  64870 MW;  BB1A204177662CE7 CRC64;
     MVYTKHIIVH KLKHLRQAKD YVENAEKTLV NESNEDHLTN LFPYISNPDK TMSKQLVSGH
     GITNVYDAAN EFIATKKLKA LSKGTDFNFD PQTGKVRFNV ESLEKNNAVL GHHLIQSFSP
     DDNLTPEQIH EIGRQTILEF TGGEYEFVIA THVDREHIHN HIIFNSTNLY TGKQFDWKVI
     PKEKTKSGKA YDVTKNNFEK VSDKIASRYG AKIIEKSPGN SHLKYTKWQT QSIYKSQIKQ
     RLDYLLEMSS DIEDFKRKAT ALNLSFDFSG KWTTYRLLDE PQMKNTRGRN LDKNRPEKYN
     LESIIERLET NELSLTVDEV VERYEEKVDV VKQDFDYQVT VEKGQIDHMT SKGFYLNVDF
     GIADRGQIFI GGYKVDQLEN RDCVLYLKKN ETFRLLSEKE ASFTKYLTGH DLAKQLGLYN
     GTVPLKKEPV ISTINQLVDA INFLAEHGVT EGTQFNNMES QLMSALGEAE EKLYVIDNKI
     MELTKIAKLL IEKESDHSQA VINELENLGV GPSIKYQDIH QELQSEKMSR KILKNKFEQT
     VDEINTFNEI RVTTLEENKG KIL