5' exonuclease Apollo (EC 3.1.-.-) (Beta-lactamase DCLRE1B) (EC 3.5.2.6) (DNA cross-link repair 1B protein) (SNM1 homolog B) (SNMIB) (hSNM1B)
1_MNGVL 6_ IPHTP 11_ IAVDF 16_ WSLRR 21_ AGTAR 26_ LFFLS 31_ HMHSD 36_ HTVGL 41_ SSTWA 46_ RPLYC 51_ SPITA 56_ HLLHR 61_ HLQVS 66_ KQWIQ 71_ ALEVG 76_ ESHVL 81_ PLDEI 86_ GQETM 91_ TVTLL 96_ DANHC 101_ PGSVM 106_ FLFEG 111_ YFGTI 116_ LYTGD 121_ FRYTP 126_ SMLKE 131_ PALTL 136_ GKQIH 141_ TLYLD 146_ NTNCN 151_ PALVL 156_ PSRQE 161_ AAHQI 166_ VQLIR 171_ KHPQH 176_ NIKIG 181_ LYSLG 186_ KESLL 191_ EQLAL 196_ EFQTW 201_ VVLSP 206_ RRLEL 211_ VQLLG 216_ LADVF 221_ TVEEK 226_ AGRIH 231_ AVDHM 236_ EICHS 241_ NMLRW 246_ NQTHP 251_ TIAIL 256_ PTSRK 261_ IHSSH 266_ PDIHV 271_ IPYSD 276_ HSSYS 281_ ELRAF 286_ VAALK 291_ PCQVV 296_ PIVSR 301_ RPCGG 306_ FQDSL 311_ SPRIS 316_ VPLIP 321_ DSVQQ 326_ YMSSS 331_ SRKPS 336_ LLWLL 341_ ERRLK 346_ RPRTQ 351_ GVVFE 356_ SPEES 361_ ADQSQ 366_ ADRDS 371_ KKAKK 376_ EKLSP 381_ WPADL 386_ EKQPS 391_ HHPLR 396_ IKKQL 401_ FPDLY 406_ SKEWN 411_ KAVPF 416_ CESQK 421_ RVTML 426_ TAPLG 431_ FSVHL 436_ RSTDE 441_ EFISQ 446_ KTREE 451_ IGLGS 456_ PLVPM 461_ GDDDG 466_ GPEAT 471_ GNQSA 476_ WMGHG 481_ SPLSH 486_ SSKGT 491_ PLLAT 496_ EFRGL 501_ ALKYL 506_ LTPVN 511_ FFQAG 516_ YSSRR 521_ FDQQV 526_EKYHK
1: 5'-3' exonuclease that plays a central role in telomere maintenance and protection during S-phase. Participates in the protection of telomeres against non-homologous end-joining (NHEJ)-mediated repair, thereby ensuring that telomeres do not fuse. Plays a key role in telomeric loop (T loop) formation by being recruited by TERF2 at the leading end telomeres and by processing leading-end telomeres immediately after their replication via its exonuclease activity: generates 3' single-stranded overhang at the leading end telomeres avoiding blunt leading-end telomeres that are vulnerable to end-joining reactions and expose the telomere end in a manner that activates the DNA repair pathways. Together with TERF2, required to protect telomeres from replicative damage during replication by controlling the amount of DNA topoisomerase (TOP1, TOP2A and TOP2B) needed for telomere replication during fork passage and prevent aberrant telomere topology. Also involved in response to DNA damage: plays a role in response to DNA interstrand cross-links (ICLs) by facilitating double-strand break formation. In case of spindle stress, involved in prophase checkpoint. Possesses beta-lactamase activity, catalyzing the hydrolysis of penicillin G and nitrocefin (PubMed:31434986). Exhibits no activity towards other beta-lactam antibiotic classes including cephalosporins (cefotaxime) and carbapenems (imipenem) (PubMed:31434986)