Selenocysteine insertion sequence-binding protein 2 (SECIS-binding protein 2)
1_MASEG 6_ PREPE 11_ SEGIK 16_ LSADV 21_ KPFVP 26_ RFAGL 31_ NVAWL 36_ ESSEA 41_ CVFPS 46_ SAATY 51_ YPFVQ 56_ EPPVT 61_ EQKIY 66_ TEDMA 71_ FGAST 76_ FPPQY 81_ LSSEI 86_ TLHPY 91_ AYSPY 96_ TLDST 101_ QNVYS 106_ VPGSQ 111_ YLYNQ 116_ PSCYR 121_ GFQTV 126_ KHRNE 131_ NTCPL 136_ PQEMK 141_ ALFKK 146_ KTYDE 151_ KKTYD 156_ QQKFD 161_ SERAD 166_ GTISS 171_ EIKSA 176_ RGSHH 181_ LSIYA 186_ ENSLK 191_ SDGYH 196_ KRTDR 201_ KSRII 206_ AKNVS 211_ TSKPE 216_ FEFTT 221_ LDFPE 226_ LQGAE 231_ NNMSE 236_ IQKQP 241_ KWGPV 246_ HSVST 251_ DISLL 256_ REVVK 261_ PAAVL 266_ SKGEI 271_ VVKNN 276_ PNESV 281_ TANAA 286_ TNSPS 291_ CTREL 296_ SWTPM 301_ GYVVR 306_ QTLST 311_ ELSAA 316_ PKNVT 321_ SMINL 326_ KTIAS 331_ SADPK 336_ NVSIP 341_ SSEAL 346_ SSDPS 351_ YNKEK 356_ HIIHP 361_ TQKSK 366_ ASQGS 371_ DLEQN 376_ EASRK 381_ NKKKK 386_ EKSTS 391_ KYEVL 396_ TVQEP 401_ PRIED 406_ AEEFP 411_ NLAVA 416_ SERRD 421_ RIETP 426_ KFQSK 431_ QQPQD 436_ NFKNN 441_ VKKSQ 446_ LPVQL 451_ DLGGM 456_ LTALE 461_ KKQHS 466_ QHAKQ 471_ SSKPV 476_ VVSVG 481_ AVPVL 486_ SKECA 491_ SGERG 496_ RRMSQ 501_ MKTPH 506_ NPLDS 511_ SAPLM 516_ KKGKQ 521_ REIPK 526_ AKKPT 531_ SLKKI 536_ ILKER 541_ QERKQ 546_ RLQEN 551_ AVSPA 556_ FTSDD 561_ TQDGE 566_ SGGDD 571_ QFPEQ 576_ AELSG 581_ PEGMD 586_ ELIST 591_ PSVED 596_ KSEEP 601_ PGTEL 606_ QRDTE 611_ ASHLA 616_ PNHTT 621_ FPKIH 626_ SRRFR 631_ DYCSQ 636_ MLSKE 641_ VDACV 646_ TDLLK 651_ ELVRF 656_ QDRMY 661_ QKDPV 666_ KAKTK 671_ RRLVL 676_ GLREV 681_ LKHLK 686_ LKKLK 691_ CVIIS 696_ PNCEK 701_ IQSKG 706_ GLDDT 711_ LHTII 716_ DYACE 721_ QNIPF 726_ VFALN 731_ RKALG 736_ RSLNK 741_ AVPVS 746_ VVGIF 751_ SYDGA 756_ QDQFH 761_ KMVEL 766_ TVAAR 771_ QAYKT 776_ MLENV 781_ QQELV 786_ GEPRP 791_ QAPPS 796_ LPTQG 801_ PSCPA 806_ EDGPP 811_ ALKEK 816_ EEPHY 821_ IEIWK 826_ KHLEA 831_ YSGCT 836_ LELEE 841_ SLEAS 846_TSQMM
1: mRNA-binding protein that binds to the SECIS (selenocysteine insertion sequence) element present in the 3'-UTR of mRNAs encoding selenoproteins and facilitates the incorporation of the rare amino acid selenocysteine (PubMed:35709277). Insertion of selenocysteine at UGA codons is mediated by SECISBP2 and EEFSEC: SECISBP2 (1) specifically binds the SECIS sequence once the 80S ribosome encounters an in-frame UGA codon and (2) contacts the RPS27A/eS31 of the 40S ribosome before ribosome stalling (PubMed:35709277). (3) GTP-bound EEFSEC then delivers selenocysteinyl-tRNA(Sec) to the 80S ribosome and adopts a preaccommodated state conformation (PubMed:35709277). (4) After GTP hydrolysis, EEFSEC dissociates from the assembly, selenocysteinyl-tRNA(Sec) accommodates, and peptide bond synthesis and selenoprotein elongation occur (PubMed:35709277)