User:Ann Taylor/SARS-CoV2 MPro: Difference between revisions

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== Overall Structure and Active Site of M protease ==

The main protease is a cysteine protease that is essential for the viral life cycle. It is forms a <scene name='95/952725/Dimer/1'>homodimer</scene> ~~consisting of the perpendicular protomers A and B~~. ~~One protomer consists of~~ <scene name='86/866577/Domains/2'>three domains</scene>. Domains I and II form an antiparallel chymotrypsin-like ß-barrel structure. Domain III (C-terminal end) consist of five alpha-helices arranged in an antiparallel cluster. <ref> Yang, H., Yang, M., Ding, Y., Liu, Y., Lou, Z., Zhou, Z., Sun, L., Mo, L., Ye, S., Pang, H., Gao, G. F., Anand, K., Bartlam, M., Hilgenfeld, R. & Rao, Z. (2003). Proc Natl Acad Sci U S A. 100, 13190–13195. </ref> <ref name=”Xu”> Xu, T., Ooi, A., Lee, H. C., Wilmouth, R., Liu, D. X. & Lescar, J. (2005). Acta Crystallogr Sect F Struct Biol Cryst Commun. 61, 964–966. </ref> The substrate binds in a <scene name='95/952725/Substrate_binding_groove/1'>channel</scene> between Domains I and II. Most of the residues in the channel are neutral (shown in white) with a few acidic residues. S1 is the <scene name='95/952725/S1_with_peptide/1'>substrate binding site</scene> and consists of the side chains Phe 140, His 163 and the backbone atoms of Glu166, Asn142, Gly 143 and His172. It confers absolute specificity for the Gln-P1 substrate residue on the enzyme as the carbonyl oxygen of Gln-P1 is stabilized by interactions with the <scene name='95/952725/Oxyanion_w_substrate/1'>backbone amide</scene> groups of Gly143 and the catalytic Cys145. <ref> Gorbalenya, A. E., Snijder, E. J. & Ziebuhr, J. (2000). Journal of General Virology. 81, 853–879. </ref> <ref> Xue, X., Yu, H., Yang, H., Xue, F., Wu, Z., Shen, W., Li, J., Zhou, Z., Ding, Y., Zhao, Q., Zhang, X. C., Liao, M., Bartlam, M. & Rao, Z. (2008). Journal of Virology. 82, 2515–2527. </ref> Hence, polyproteins are cleaved within the Leu-Gln↓(Ser, Ala, Gly) sequence. <ref> Rut, W., Groborz, K., Zhang, L., Sun, X., Zmudzinski, M., Hilgenfeld, R. & Drag, M. (2020). BioRxiv. 2020.03.07.981928. </ref>

The main protease is a cysteine protease that is essential for the viral life cycle. It is forms a <scene name='95/952725/Dimer/1'>homodimer</scene> arranged perpendicularly. Each protein chain has <scene name='86/866577/Domains/2'>three domains</scene>. Domains I and II form an antiparallel chymotrypsin-like ß-barrel structure. Domain III (C-terminal end) consist of five alpha-helices arranged in an antiparallel cluster. <ref> Yang, H., Yang, M., Ding, Y., Liu, Y., Lou, Z., Zhou, Z., Sun, L., Mo, L., Ye, S., Pang, H., Gao, G. F., Anand, K., Bartlam, M., Hilgenfeld, R. & Rao, Z. (2003). Proc Natl Acad Sci U S A. 100, 13190–13195. </ref> <ref name=”Xu”> Xu, T., Ooi, A., Lee, H. C., Wilmouth, R., Liu, D. X. & Lescar, J. (2005). Acta Crystallogr Sect F Struct Biol Cryst Commun. 61, 964–966. </ref> The substrate binds in a <scene name='95/952725/Substrate_binding_groove/1'>channel</scene> between Domains I and II. Most of the residues in the channel are neutral (shown in white) with a few acidic residues. S1 is the <scene name='95/952725/S1_with_peptide/1'>substrate binding site</scene> and consists of the side chains Phe 140, His 163 and the backbone atoms of Glu166, Asn142, Gly 143 and His172. It confers absolute specificity for the Gln-P1 substrate residue on the enzyme as the carbonyl oxygen of Gln-P1 is stabilized by interactions with the <scene name='95/952725/Oxyanion_w_substrate/1'>backbone amide</scene> groups of Gly143 and the catalytic Cys145. <ref> Gorbalenya, A. E., Snijder, E. J. & Ziebuhr, J. (2000). Journal of General Virology. 81, 853–879. </ref> <ref> Xue, X., Yu, H., Yang, H., Xue, F., Wu, Z., Shen, W., Li, J., Zhou, Z., Ding, Y., Zhao, Q., Zhang, X. C., Liao, M., Bartlam, M. & Rao, Z. (2008). Journal of Virology. 82, 2515–2527. </ref> Hence, polyproteins are cleaved within the Leu-Gln↓(Ser, Ala, Gly) sequence. <ref> Rut, W., Groborz, K., Zhang, L., Sun, X., Zmudzinski, M., Hilgenfeld, R. & Drag, M. (2020). BioRxiv. 2020.03.07.981928. </ref>

The active site involves a <scene name='86/866577/Active_site/2'>catalytic dyad</scene> consisting of the residues Cys145 and His41. It forms a covalent intermediate with the substrate in a similar fashion to a [[serine protease]].

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 == Overall Structure and Active Site of M protease ==
-The main protease is a cysteine protease that is essential for the viral life cycle. It is forms a <scene name='95/952725/Dimer/1'>homodimer</scene> consisting of the perpendicular protomers A and B. One protomer consists of <scene name='86/866577/Domains/2'>three domains</scene>. Domains I and II form an antiparallel chymotrypsin-like ß-barrel structure. Domain III (C-terminal end) consist of five alpha-helices arranged in an antiparallel cluster. <ref> Yang, H., Yang, M., Ding, Y., Liu, Y., Lou, Z., Zhou, Z., Sun, L., Mo, L., Ye, S., Pang, H., Gao, G. F., Anand, K., Bartlam, M., Hilgenfeld, R. & Rao, Z. (2003). Proc Natl Acad Sci U S A. 100, 13190–13195. </ref> <ref name=”Xu”> Xu, T., Ooi, A., Lee, H. C., Wilmouth, R., Liu, D. X. & Lescar, J. (2005). Acta Crystallogr Sect F Struct Biol Cryst Commun. 61, 964–966. </ref>  The substrate binds in a <scene name='95/952725/Substrate_binding_groove/1'>channel</scene> between Domains I and II.  Most of the residues in the channel are neutral (shown in white) with a few acidic residues.  S1 is the <scene name='95/952725/S1_with_peptide/1'>substrate binding site</scene> and consists of the side chains Phe 140, His 163 and the backbone atoms of Glu166, Asn142, Gly 143 and His172. It confers absolute specificity for the Gln-P1 substrate residue on the enzyme as the carbonyl oxygen of Gln-P1 is stabilized by interactions with the <scene name='95/952725/Oxyanion_w_substrate/1'>backbone amide</scene> groups of Gly143 and the catalytic Cys145. <ref> Gorbalenya, A. E., Snijder, E. J. & Ziebuhr, J. (2000). Journal of General Virology. 81, 853–879. </ref> <ref> Xue, X., Yu, H., Yang, H., Xue, F., Wu, Z., Shen, W., Li, J., Zhou, Z., Ding, Y., Zhao, Q., Zhang, X. C., Liao, M., Bartlam, M. & Rao, Z. (2008). Journal of Virology. 82, 2515–2527.  </ref> Hence, polyproteins are cleaved within the Leu-Gln↓(Ser, Ala, Gly) sequence. <ref> Rut, W., Groborz, K., Zhang, L., Sun, X., Zmudzinski, M., Hilgenfeld, R. & Drag, M. (2020). BioRxiv. 2020.03.07.981928. </ref>
+The main protease is a cysteine protease that is essential for the viral life cycle. It is forms a <scene name='95/952725/Dimer/1'>homodimer</scene> arranged perpendicularly. Each protein chain has <scene name='86/866577/Domains/2'>three domains</scene>. Domains I and II form an antiparallel chymotrypsin-like ß-barrel structure. Domain III (C-terminal end) consist of five alpha-helices arranged in an antiparallel cluster. <ref> Yang, H., Yang, M., Ding, Y., Liu, Y., Lou, Z., Zhou, Z., Sun, L., Mo, L., Ye, S., Pang, H., Gao, G. F., Anand, K., Bartlam, M., Hilgenfeld, R. & Rao, Z. (2003). Proc Natl Acad Sci U S A. 100, 13190–13195. </ref> <ref name=”Xu”> Xu, T., Ooi, A., Lee, H. C., Wilmouth, R., Liu, D. X. & Lescar, J. (2005). Acta Crystallogr Sect F Struct Biol Cryst Commun. 61, 964–966. </ref>  The substrate binds in a <scene name='95/952725/Substrate_binding_groove/1'>channel</scene> between Domains I and II.  Most of the residues in the channel are neutral (shown in white) with a few acidic residues.  S1 is the <scene name='95/952725/S1_with_peptide/1'>substrate binding site</scene> and consists of the side chains Phe 140, His 163 and the backbone atoms of Glu166, Asn142, Gly 143 and His172. It confers absolute specificity for the Gln-P1 substrate residue on the enzyme as the carbonyl oxygen of Gln-P1 is stabilized by interactions with the <scene name='95/952725/Oxyanion_w_substrate/1'>backbone amide</scene> groups of Gly143 and the catalytic Cys145. <ref> Gorbalenya, A. E., Snijder, E. J. & Ziebuhr, J. (2000). Journal of General Virology. 81, 853–879. </ref> <ref> Xue, X., Yu, H., Yang, H., Xue, F., Wu, Z., Shen, W., Li, J., Zhou, Z., Ding, Y., Zhao, Q., Zhang, X. C., Liao, M., Bartlam, M. & Rao, Z. (2008). Journal of Virology. 82, 2515–2527.  </ref> Hence, polyproteins are cleaved within the Leu-Gln↓(Ser, Ala, Gly) sequence. <ref> Rut, W., Groborz, K., Zhang, L., Sun, X., Zmudzinski, M., Hilgenfeld, R. & Drag, M. (2020). BioRxiv. 2020.03.07.981928. </ref>
 The active site involves a <scene name='86/866577/Active_site/2'>catalytic dyad</scene> consisting of the residues Cys145 and His41.  It forms a covalent intermediate with the substrate in a similar fashion to a [[serine protease]].