ID 2.3.2.5 DE glutaminyl-peptide cyclotransferase. AN glutaminyl cyclase. AN glutaminyl-tRNA cyclotransferase. CA N-terminal L-glutaminyl-[peptide] = N-terminal 5-oxo-L-prolyl-[peptide] + CA NH4(+). CC -!- Involved in the formation of thyrotropin-releasing hormone and other CC biologically active peptides containing N-terminal pyroglutamyl CC residues. CC -!- The enzyme from papaya also acts on glutaminyl-tRNA. DR Q9VRQ9, QPCT1_DROME; Q86PD7, QPCT2_DROME; Q0V8G3, QPCTL_BOVIN; DR Q9NXS2, QPCTL_HUMAN; Q4R942, QPCTL_MACFA; Q8BH73, QPCTL_MOUSE; DR Q84WV9, QPCT_ARATH ; A7ISW2, QPCT_BOIDE ; A7ISW1, QPCT_BOIIR ; DR Q9YIB5, QPCT_BOTJA ; Q28120, QPCT_BOVIN ; P0CV92, QPCT_CROAT ; DR Q54B14, QPCT_DICDI ; Q90YA8, QPCT_GLOBL ; Q16769, QPCT_HUMAN ; DR B7QK46, QPCT_IXOSC ; Q9CYK2, QPCT_MOUSE ; //