Mammalian prothymosin alpha links to tRNA in Escherichia coli cells.
Prothymosin alpha, a small and highly acidic nuclear protein related to cell proliferation, is known to be covalently attached to a small unidentified cytoplasmic RNA in mammalian cells. Here we demonstrate that recombinant rat prothymosin a links covalently to an RNA when overproduced in Escherichia coli cells. The RNA species of this complex is represented by a wide range of bacterial tRNAs. tRNA(Lys), tRNA(3Ser), tRNA(2Ile), and tRNA(mMet) were identified by sequencing. Prothymosin alpha appears to be linked to the 5' terminus of tRNA. tRNA attachment site lies close to the carboxy-terminus of prothymosin alpha. Furthermore, the carboxy-terminal peptide of prothymosin alpha is also competent for tRNA binding. The site of tRNA attachment coincides with the nuclear localization signal of prothymosin alpha, and tRNA binding might be expected to affect subcellular localization of this protein.
Vartapetian
A
A
Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia. vart@nucleo.genebee.msu.su.
Lukashev
D
D
Lyakhov
I
I
Belyaeva
A
A
Chichkova
N
N
Bogdanov
A
A
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000737:chemistry; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009690:Nucleic Acid Conformation; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011498:Protein Precursors / Q000737:chemistry / Q000378:metabolism*; D012329:RNA, Bacterial / Q000378:metabolism; D012343:RNA, Transfer / Q000378:metabolism*; D012357:RNA, Transfer, Lys / Q000378:metabolism; D012358:RNA, Transfer, Met / Q000378:metabolism; D012362:RNA, Transfer, Ser / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D017423:Sequence Analysis, RNA; D013947:Thymosin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism
D010446:Peptide Fragments; D011498:Protein Precursors; D012329:RNA, Bacterial; D012357:RNA, Transfer, Lys; D012358:RNA, Transfer, Met; D012362:RNA, Transfer, Ser; D011994:Recombinant Proteins; C040782:prothymosin alpha; D013947:Thymosin; D012343:RNA, Transfer; D014357:Trypsin