- The enzyme is a 3'-5' nucleic acid ligase with the ability to join
RNA with 3'-phosphate or 2',3'-cyclic-phosphate ends to RNA with
5'-hydroxy ends.
- It can also join DNA with 3'-phosphate ends to DNA with 5'-hydroxy
ends, provided the DNA termini are unpaired.
- The enzyme is found in members of all three kingdoms of life, and is
essential in metazoa for the splicing of intron-containing tRNAs.
- The reaction follows a three-step mechanism with initial activation
of the enzyme by GTP hydrolysis, forming a phosphoramide bond between
the guanylate and a histidine residue.
- The guanylate group is transferred to the 3'-phosphate terminus of
the substrate, forming the capped structure [DNA/RNA]-
3'-(5'-diphosphoguanosine).
- When a suitable 5'-OH end is available, the enzyme catalyzes an
attack of the 5'-OH on the capped end to form a 3'-5' phosphodiester
splice junction, releasing the guanylate.
- When acting on an RNA 2',3'-cyclic-phosphate, the enzyme catalyzes an
additional reaction, hydrolyzing the cyclic phosphate to a
3'-phosphate.
- The metazoan enzyme requires activating cofactors in order to achieve
multiple turnover catalysis.
|
UniProtKB/Swiss-Prot |
B0WCT9, RTCB1_CULQU | P0DX92, RTCB1_ECOS1 | B0EAV2, RTCB1_ENTDS |
C4M244, RTCB1_ENTH1 | B0XKF3, RTCB2_CULQU | P0DX91, RTCB2_ECOS1 |
B0EIW5, RTCB2_ENTDS | C4M6T2, RTCB2_ENTH1 | Q17FP1, RTCB_AEDAE |
Q9YB37, RTCB_AERPE | Q7Q412, RTCB_ANOGA | O29399, RTCB_ARCFU |
Q5E9T9, RTCB_BOVIN | C3YN79, RTCB_BRAFL | A8QC60, RTCB_BRUMA |
P90838, RTCB_CAEEL | A8JC00, RTCB_CHLRE | Q6NZS4, RTCB_DANRE |
Q54Y09, RTCB_DICDI | Q9VIW7, RTCB_DROME | P46850, RTCB_ECOLI |
Q9Y3I0, RTCB_HUMAN | Q4R6X4, RTCB_MACFA | Q58095, RTCB_METJA |
Q8TUS2, RTCB_METKA | Q6LXF9, RTCB_METMP | O27634, RTCB_METTH |
C1E9Y5, RTCB_MICCC | C1MI97, RTCB_MICPC | A9UXG6, RTCB_MONBE |
Q99LF4, RTCB_MOUSE | P59975, RTCB_MYCBO | P9WGW4, RTCB_MYCTO |
P9WGW5, RTCB_MYCTU | Q74MJ0, RTCB_NANEQ | A7RKF6, RTCB_NEMVE |
A4S3S3, RTCB_OSTLU | Q00ZY2, RTCB_OSTTA | A9CB42, RTCB_PAPAN |
Q19PY3, RTCB_PIG | Q4YUZ9, RTCB_PLABA | Q8IIU6, RTCB_PLAF7 |
B3L4K9, RTCB_PLAKH | Q7RI54, RTCB_PLAYO | Q9V168, RTCB_PYRAB |
Q8ZY09, RTCB_PYRAE | Q8U0H4, RTCB_PYRFU | O59245, RTCB_PYRHO |
Q6AYT3, RTCB_RAT | B8LBM8, RTCB_THAPS | Q4U923, RTCB_THEAN |
Q5JCZ1, RTCB_THEKO | Q4N1R8, RTCB_THEPA | B3RID0, RTCB_TRIAD |
Q561P3, RTCB_XENTR |
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