G6-16 aptamer



Timeline

An aptamer called 10G-1, which binds specifically to the NS3 protease, was selected for the first time by in vitro genetic-selection strategy[1]

Nishikawa, S. et al. isolated aptamers that inhibited the activity of NS3 protease and helicase[2]

Nishikawa, S. et al. isolated RNA aptamers that bind specifically to the NS3 protease active site in the truncated polypeptide ΔNS3[3]

The binding sites of NS3 protease domain and aptamer were analyzed by alanine scanning mutagenesis[4]

Nishikawa, S. et al. constructed a G9 aptamer expression system in cultured cells, using the cytomegarovirus enhancer + chicken beta-actin globin (CAG) promoter[5]

Lee, S. W. et al. isolated specific RNA aptamers to the helicase domain of HCV NS3 from a combinatorial RNA library with 40-nucleotide random sequences using in vitro selection techniques[6]

Nishikawa, S. et al. designed a new aptamer called NEO-III-14U to inhibit both protease and helicase activity[7]

Kao, C. C. et al. showed that RNAs can bind directly to the active site cleft of the NS3 protease domain (NS3P) and inhibit proteolysis of peptide substrates. RNAs that are less apt to form intramolecular structures have a stronger inhibitory activity than RNAs with more stable base paired regions[8]

Description

In 1997, Nishikawa, S. and colleagues used a genetic selection strategy in vitro to isolate, from a pool of completely random RNA (120 random bases), those RNA aptamers that could bind to NS3. After six cycles of selection and amplification, 14% of the pooled RNAs could bind specifically to the NS3 protein. When the aptamers in the pool (cycle 6) were analyzed for binding and inhibition of the proteolytic activity of NS3 with the NS5A/NS5B peptide as substrate (S1), two aptamers, designated G6-16 and G6-19 RNA, were found to inhibit NS3 in vitro. Kinetic studies of the inhibition revealed that the aptamer G6-16 inhibited the NS3 protease with an inhibitory constant (Ki) of 3 microM[2].



SELEX

In 1997, Nishikawa, S. and colleagues designed a selecting method based on existing research. They used a genetic selection strategy in vitro to isolate, from a pool of completely random RNA (120 random bases), those RNA aptamers that could bind to NS3. After six cycles of selection and amplification, 14% of the pooled RNAs could bind specifically to the NS3 protein. When the aptamers in the pool (cycle 6) were analyzed for binding and inhibition of the proteolytic activity of NS3 with the NS5A/NS5B peptide as substrate (S1), two aptamers, designated G6-16 and G6-19 RNA, were found to inhibit NS3 in vitro[2].

Detailed information are accessible on SELEX page.



Structure

G6-16 was the aptamer sequence mainly studied in the article, which had a high affinity with HCV NS3 protein. The 2D structure of the figure is based on the article by ribodraw tool to draw. The G6-16 aptamer was named by Nishikawa, S. et al. in the article[2].

5'-GGGAGAAUUCCGACCAGAAGGCUUGCUGUUGUUUCCCUGUUGUUUUGUCUCUCAACUUUAUUGUGGUAAAGAUCACUGGGUUGAUAAGGGCUAACUCUAAUUUGACUACAUGGUCGGACCAAUCAGUUCUUAUGGGAGAUGCAUAUGUGCGUCUACAUGGAUCCUCA-3'

drawing


Ligand information

SELEX ligand

Hepatitis C virus NS3 protein is a serine protease which has a trypsin-like fold. The non-structural (NS) protein NS3 is one of the NS proteins involved in replication of the HCV genome. The action of NS3 protease (NS3P), which resides in the N-terminal one-third of the NS3 protein, then yields all remaining non-structural proteins.-----From Pfam

UniProt ID: uniquely identifies protein sequences in the UniProt database, a resource for protein information.

Pfam: a widely recognised database of protein families and domains.

GenBank: maintained by NCBI(National Center for Biotechnology Information), is a database of nucleotide sequences from various organisms, vital for genetic and molecular biology research.

Mass: an intrinsic property of a body.

Name Uniprot ID Pfam Mass Protein sequence PDB ID GenBank
HCV NS3 protease B2Y2M9 PF02907 19.15 kDa
...... APITAYAQQTRGLLGCIITSLTGRDKNQVEGEVQIVSTATQTFLATCINGVCWTVYHGAGTRTIASPKGPVIQMYTNVDQDLVGWPAPQGSRSLTPCTCGSSDLYLVTRHADVIPVRRRGDSRGSLLSPRPISYLKGSSGGPLLCPAGHAVGLFRAAVCTRGVAKAVDFIPVENLETTMRS (Residues 1027-1207)
3KF2 ABY67662.1

Some isolated sequences bind to the affinity of the protein[1].

Name Sequence Ligand Affinity
G6-16 5'-GGGAGAAUUCCGACCAGAAGGCUUGCUGUUGUUUCCCUGUUGUUUUGUCUCUCAACUUUAUUGUGGUAAAGAUCACUGGGUUGAUAAGGGCUAACUCUAAUUUGACUACAUGGUCGGACCAAUCAGUUCUUAUGGGAGAUGCAUAUGUGCGUCUACAUGGAUCCUCA-3' HCV NS3 protein 120 ± 18 nM
△G6-16 5'-GGGAGAAUUCCGACCAGAAGGCUUGCUGUUGUUUCCCUGUUGUUUUGUCUCUCAACUUUAUUGUGGUAAAGAUCACUGGGUUGAUAAGGGCUAACUCUAAUUUGACUACAUGG-3' HCV NS3 protein 238 ± 110 nM
G6-19 5'-GGGAGAAUUCCGACCAGAAGCUUAUACUGAAUUAAUCGCUACCGUGUCAUUGUACUUGGUAGUGUUGAUGGUUUGGGUCGCAUUUGGCUUGGCUUAUGGUUUUUUCACCCUACCUCUCAUUGACGCACUAGGCUCUCAUAUGUGCGUCUACAUGGAUCCUCA-3' HCV NS3 protein NA
drawing

Similar compound(s)

We used the Dail server website to compare the structural similarities of ligand proteins, and chose the top 10 in terms of similarity for presentation.

Dail server website: a network service for comparing protein structures in 3D. Dali compares them against those in the Protein Data Bank (PDB).

Z-score: a standard score that is converted from an original score. The list of neighbours is sorted by Z-score. Similarities with a Z-score lower than 2 are spurious.

RMSD: (Root Mean Square Deviation) is used to measure the degree to which atoms deviate from the alignment position.

PDB: PDB ID+ chain name.

PDB Z-socre RMSD (Å) Description
3KF2-B 37.5 0 Polyprotein
2OIN-B 35.7 0.3 Polyprotein
2O8M-A 35.7 0.3 Protease
3LON-A 35.5 0.3 Genome polyprotein
2OC0-A 35.5 0.3 Hepatitis C virus
2A4R-A 35.3 0.3 NS3 protease/helicase
2QV1-B 35.3 0.3 NS3
3KN2-A 35.3 0.3 HCV NS3 protease domain
2A4Q-A 35.3 0.3 NS3 protease/helicase
3EYD-A 35.3 0.3 HCV NS3


References

[1] Selection of RNA aptamers that bind specifically to the NS3 protease of hepatitis C virus.
Urvil, P. T., Kakiuchi, N., Zhou, D. M., Shimotohno, K., Kumar, P. K., & Nishikawa, S.
European journal of biochemistry, 248(1), 130–138. (1997)
[2] Isolation of RNA aptamers specific to the NS3 protein of hepatitis C virus from a pool of completely random RNA.
Kumar, P. K., Machida, K., Urvil, P. T., Kakiuchi, N., Vishnuvardhan, D., Shimotohno, K., Taira, K., & Nishikawa, S.
Virology, 237(2), 270–282. (1997)
[3] Isolation and characterization of RNA aptamers specific for the hepatitis C virus nonstructural protein 3 protease.
Fukuda, K., Vishnuvardhan, D., Sekiya, S., Hwang, J., Kakiuchi, N., Taira, K., Shimotohno, K., Kumar, P. K., & Nishikawa, S.
European journal of biochemistry, 267(12), 3685–3694. (2000)
[4] The RNA aptamer-binding site of hepatitis C virus NS3 protease.
Hwang, J., Fauzi, H., Fukuda, K., Sekiya, S., Kakiuchi, N., Shimotohno, K., Taira, K., Kusakabe, I., & Nishikawa, S.
Biochemical and biophysical research communications, 279(2), 557–562. (2000)
[5] Inhibition of HCV NS3 protease by RNA aptamers in cells.
Nishikawa, F., Kakiuchi, N., Funaji, K., Fukuda, K., Sekiya, S., & Nishikawa, S.
Nucleic acids research, 31(7), 1935–1943. (2003)
[6] Isolation of specific and high-affinity RNA aptamers against NS3 helicase domain of hepatitis C virus.
Hwang, B., Cho, J. S., Yeo, H. J., Kim, J. H., Chung, K. M., Han, K., Jang, S. K., & Lee, S. W.
RNA (New York, N.Y.), 10(8), 1277–1290. (2004)
[7] An RNA ligand inhibits hepatitis C virus NS3 protease and helicase activities.
Fukuda, K., Umehara, T., Sekiya, S., Kunio, K., Hasegawa, T., & Nishikawa, S.
Biochemical and biophysical research communications, 325(3), 670–675. (2004)
[8] RNA binding by the NS3 protease of the hepatitis C virus.
Vaughan, R., Li, Y., Fan, B., Ranjith-Kumar, C. T., & Kao, C. C.
Virus research, 169(1), 80–90. (2012)