KEY RESOURCES TABLE

REAGENT or RESOURCE	SOURCE	IDENTIFIER
Bacterial and virus strains
E.coli: BL21(DE3) Competent cells	Novagen	Cat#69450–3
E.coli: DH5α Competent cells	ThermoFisher	Cat#18265017
E.coli: Turbo Competent cells	Weidi	Cat#DL1081
Chemicals, peptides, and recombinant proteins
ULP1	Home-made	N/A
T7 RNA polymerase	Home-made	N/A
Urea	Sangon Biotech	CAS: 57-13-6 Cat#A610148-0500
Diethyl pyrocarbonate	Sangon Biotech	CAS: 1609-47-8 Cat#B600154-0100
40% acrylamide and bis-acrylamide solution, 29:1	Sangon Biotech	Cat#B546013–0500
Critical commercial assays
PureLink HiPure Plasmid Megaprep Kit	ThermoFisher	Cat#K210008
Deposited data
Coordinate of LshCas13a-crRNA-anti-tag RNA ternary complex	This paper	PDB: 7DMQ
Density map of LshCas13a-crRNA-anti-tag RNA ternary complex	This paper	EMDB: EMD-30767
Recombinant DNA
pRSF-Duet-1-His6-SUMO-LshCas13a, wild-type and various mutants	This paper	N/A
pRSF-Duet-1-His6-SUMO-LbuCas13a, wild-type and various mutants	This paper	N/A
pUT7-LshCas13a crRNA, wild-type and mutant	This paper	N/A
pUT7-LbuCas13a crRNA, wild-type and mutant	This paper	N/A
pUT7-target RNA (RNA1–6, 21-spacer RNA)	This paper	N/A
pUT7-non-target RNA	This paper	N/A
pCDF-Duet-1-LshCas13a-CRISPR, wild-type and various mutants	This paper	N/A
pRSF-Duet-1-LbuCas13a-CRISPR, wild-type and various mutants	This paper	N/A
pBR322-EYFP, with or without anti-tag sequence	This paper	N/A
Oligonucleotides
56-nt LshCas13a crRNA: GGCCACCCCAAUAUCGAAGGGGACUAAAACUAGAUUGCUGUUCUACCAAGUAAUCCAU	This paper	N/A
57-nt LbuCas13a crRNA: GGACCACCCCAAAAAUGAAGGGGACUAAAACUAGAUUGCUGUUCUACCAAGUAAUCCAU	This paper	N/A
50-nt LbuCas13a crRNA: GGACCACCCCAAAAAUGAAGGGGACUAAAACUAGAUUGCUGUUCUACCAAGU	This paper	N/A
Target RNA1: GGGAAGUUCAACUCUUUAUGUAUUGAUCUUCCAAAAUauggauuacuugguagaacagcaaucuaCUC	This paper	N/A
Target RNA2: GGGAAGUUCAACUCUUUAUGUAUUGAUCUUCCAAAAUauggauuacuugguagaacagcaaucuaGUUUUCUC	This paper	N/A
Target RNA3: GGGAAGUUCAACUCUUUAUGUAUUGAUCUUCCAAAAUauggauuacuugguagaacagcaaucuaGUUUUAGUCUC	This paper	N/A
Target RNA4: GauggauuacuugguagaacagcaaucuaCAAAAUCA	IDT	N/A
Target RNA5: GauggauuacuugguagaacagcaaucuaGUUUUUCA	IDT	N/A
Target RNA6: GauggauuacuugguagaacagcaaucuaGUUUUAGU	IDT	N/A
21-nt Target RNA without anti-tag: GacuugguagaacagcaaucuaCAAAAUCA	IDT	N/A
21-nt Target RNA with anti-tag: GacuugguagaacagcaaucuaGUUUUAGU	IDT	N/A
102-nt non-target RNA: GGAUAACUCAAUUUGUAAAAAAGUUUUAGAGCUAGAAAUAGCAAGUUAAAAUAAGGCUAGUCCGUUAUCAACUUGAAAAAGUGGCACCGAGUCGGUGCUUUC	This paper	N/A
Software and algorithms
Coot	Emsley et al., 2010	https://www2.mrc-lmb.cam.ac.uk/personal/pemsley/coot; RRID:SCR_014222
Phenix	Adams et al., 2010	https://www.phenix-online.org; RRID: SCR_014224
SerialEM data collection software	Mastronarde, 2005	https://bio3d.colorado.edu/SerialEM/; RRID: SCR_017293
MotionCor2	Zheng et al., 2017	https://msg.ucsf.edu/em/software/motioncor2.html; RRID: SCR_016499
CTFFIND4	Rohou and Grigorieff, 2015	https://grigoriefflab.janelia.org/ctffind4/; RRID: SCR_016732
RELION	Scheres, 2012	https://www3.mrc-lmb.cam.ac.uk/relion//index.php?title=Main_Page%2F; RRID: SCR_016274
ResMap	Kucukelbir et al., 2014	http://resmap.sourceforge.net/
USCF Chimera	Pettersen et al., 2004	https://www.cgl.ucsf.edu/chimera/; RRID: SCR_004097
PyMOL	The PyMOL Molecular Graphics System, Version 2.2.3, Schrodinger, LLC	https://pymol.org/2/; RRID: SCR_000305
CueMol	Version 2.2.3.434	http://www.cuemol.org; RRID: SCR_019052
Clustal Omega	Madeira et al., 2019	https://www.ebi.ac.uk/Tools/msa/clustalo/; RRID: SCR_001591
PRISM	Version 7.0	https://www.graphpad.com/scientific-software/prism/; RRID: SCR_002798
Other
Amicon concentrators (30K)	Millipore	Cat#UFC903024
HisTrap FF (5 ml)	GE Healthcare	Cat#17-5255-01
HiTrap Heparin HP (5 ml)	GE Healthcare	Cat#17-0407-03
HiLoad 16/600 Superdex 200 pg	GE Healthcare	Cat#28989335
Superdex 200 10/300 GL	GE Healthcare	Cat#17517501
UltrAufoil R1.2/1.3 300 mesh grids	Quantifoil	Cat# BQRU1.2/1.3–3A-B
Whatman Elutrap electroelution system	Sigma-Aldrich	Cat#WHA10447700