REAGENT or RESOURCE	SOURCE	IDENTIFIER
Chemicals, peptides, and recombinant proteins
DMEM, high glucose, GlutaMAX Supplement	Thermo Fisher	10566024
Heat-inactivated FBS	Life Technologies	10082-147
Polybrene	Sigma	TR-1003
Puromycin dihydrochloride	Thermo Fisher	A1113803
Klenow fragment 3′-to-5′ exo-minus	New England Biolabs	M0212S
Streptavidin	New England Biolabs	N7021S
Heparin	Sigma	H4784
Protocatechuic acid	Aldrich	37580
Pseudomonas sp. protocatechuate 3,4-Dioxygenase	Sigma	P8279
Trolox	Aldrich	238813
Propyl gallate	Sigma	P3130
4-nitrobenzyl alcohol	Aldrich	N12821
Proteinase K	EMD Millipore	70663-5
AccuPrime Pfx DNA Polymerase	Invitrogen	12344024
3XFLAG	Sigma Aldrich	F4799
Critical commercial assays
Anti-FLAG M2 paramagnetic beads	Sigma	M8823
Dynabeads MyOne Streptavidin T1	Life Technologies	65602
Protran nitrocellulose	Sigma	GE10600002
Hybond-XL	Cytiva	RPN303S
SuperScript III First-Strand Synthesis System	Invitrogen	18080051
TransIT-2020	Mirus Bio	MIR 5406
Deposited data
Raw sequencing data from mouse RISC RBNS	This study	NCBI: PRJNA807105
Raw sequencing data from human RISC RBNS	McGeary et al. (2019)	GSE140220
Experimental models: Cell lines
HEK 293T stably overexpressing FLAG-tagged mouse AGO2	This study	N/A
Oligonucleotides
Table S1	This study	N/A
Recombinant DNA
pScalps Puro EGFP 3XFLAG-AGO2	This study	N/A
psPAX2	Gift of Ken-Edwin Aryee	N/A
pMD2.G	Gift of Ken-Edwin Aryee	N/A
Software and algorithms
Python v2.7.11	Python Software Foundation	https://www.python.org
Python module NumPy v1.16.6	Harris et al., 2020	https://numpy.org/
Python module SciPy v1.2.3	Virtanen et al., 2020	http://www.scipy.org
MATLAB vR2020b	Natick, MA: MathWorks	https://www.mathworks.com
CoSMoS pipeline v1	Smith et al. (2019)	https://github.com/qnano/cosmos_pipeline
Estimation of KD values and kinetic parameters	This study	https://doi.org/10.6084/m9.figshare.19180952