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Solution structure of the 2A protease from a common cold agent, human rhinovirus C2, strain W12.

Lee W, Watters KE, Troupis AT, Reinen NM, Suchy FP, Moyer KL, Frederick RO, Tonelli M, Aceti DJ, Palmenberg AC, Markley JL - PLoS ONE (2014)

Bottom Line: The catalytic triad consists of conserved Cys (C105), His (H34), and Asp (D18) residues.The backbone of C2 2Apro superimposed closely (1.41-1.81 Å rmsd) with those of orthologs from RV-A2, coxsackie B4 (CB4), and enterovirus 71 (EV71) having sequence identities between 40% and 60%.Comparison of the structures suggest that the differential functional properties of C2 2Apro stem from its unique surface charge, high proportion of surface aromatics, and sequence surrounding the di-tyrosine flap.

View Article: PubMed Central - PubMed

Affiliation: National Magnetic Resonance Facility at Madison, Biochemistry Department, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.

ABSTRACT
Human rhinovirus strains differ greatly in their virulence, and this has been correlated with the differing substrate specificity of the respective 2A protease (2Apro). Rhinoviruses use their 2Apro to cleave a spectrum of cellular proteins important to virus replication and anti-host activities. These enzymes share a chymotrypsin-like fold stabilized by a tetra-coordinated zinc ion. The catalytic triad consists of conserved Cys (C105), His (H34), and Asp (D18) residues. We used a semi-automated NMR protocol developed at NMRFAM to determine the solution structure of 2Apro (C105A variant) from an isolate of the clinically important rhinovirus C species (RV-C). The backbone of C2 2Apro superimposed closely (1.41-1.81 Å rmsd) with those of orthologs from RV-A2, coxsackie B4 (CB4), and enterovirus 71 (EV71) having sequence identities between 40% and 60%. Comparison of the structures suggest that the differential functional properties of C2 2Apro stem from its unique surface charge, high proportion of surface aromatics, and sequence surrounding the di-tyrosine flap.

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Sequence alignment of C2, A2, CB4, and EV71 2Apro.Residues are color-coded by type. Residues in the catalytic triad (C2: H18, D34, and C105A) are boxed with solid lines. Residues whose side chains ligate the zinc ion (C2: C51, C53, C111, H113) are boxed with dashed lines. The ellipse highlights the conserved YYP sequence in the di-tyrosine flap. Symbols above the sequences indicate secondary structural features as per Figure 3.
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pone-0097198-g007: Sequence alignment of C2, A2, CB4, and EV71 2Apro.Residues are color-coded by type. Residues in the catalytic triad (C2: H18, D34, and C105A) are boxed with solid lines. Residues whose side chains ligate the zinc ion (C2: C51, C53, C111, H113) are boxed with dashed lines. The ellipse highlights the conserved YYP sequence in the di-tyrosine flap. Symbols above the sequences indicate secondary structural features as per Figure 3.

Mentions: The C2 2Apro is the first protein from an RV-C to be examined at the structural level. Among enteroviruses, the only viral genus to have such enzymes, structures were previously reported for 2Apro from RV-A2 [11] and EV-71 [13] determined by crystallography and EV-CB4 [14] determined by NMR. The sequence identities are 57% between A2 and C2, 41% between CB4 and C2, and 40% between EV71 and C2. Structure alignments show that the only relative indels are confined to a short stretch in the first domain (before eI2) and to length discontinuities at the N- and C-terminal cleavage sites (Figure 7). For comparison, important structural and functional elements are highlighted on this map. The substrate-binding di-tyrosine flap (YYP) is marked by an ellipse. The one His (H113) and three Cys residues (C51, C53, C111dashed boxes) responsible for coordinating the structural zinc ion (Figure 5Bgray sphere) converge on the back side of the molecule, basically holding the main domains together. Sequencing studies have highlighted a number of RV isolates that are apparent recombinants within the 2Apro region [42]. When this occurs, invariably, within or between RV-A and RV-C strains, the identified breakpoints cluster in the central linker region and at the C-terminus, swapping the intact N- and C-terminal domains. That these recombinants are apparently fully functional suggests that the two main domains fold independently, with each domain contributing zinc coordination elements that stabilize the full enzyme.


Solution structure of the 2A protease from a common cold agent, human rhinovirus C2, strain W12.

Lee W, Watters KE, Troupis AT, Reinen NM, Suchy FP, Moyer KL, Frederick RO, Tonelli M, Aceti DJ, Palmenberg AC, Markley JL - PLoS ONE (2014)

Sequence alignment of C2, A2, CB4, and EV71 2Apro.Residues are color-coded by type. Residues in the catalytic triad (C2: H18, D34, and C105A) are boxed with solid lines. Residues whose side chains ligate the zinc ion (C2: C51, C53, C111, H113) are boxed with dashed lines. The ellipse highlights the conserved YYP sequence in the di-tyrosine flap. Symbols above the sequences indicate secondary structural features as per Figure 3.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4061012&req=5

pone-0097198-g007: Sequence alignment of C2, A2, CB4, and EV71 2Apro.Residues are color-coded by type. Residues in the catalytic triad (C2: H18, D34, and C105A) are boxed with solid lines. Residues whose side chains ligate the zinc ion (C2: C51, C53, C111, H113) are boxed with dashed lines. The ellipse highlights the conserved YYP sequence in the di-tyrosine flap. Symbols above the sequences indicate secondary structural features as per Figure 3.
Mentions: The C2 2Apro is the first protein from an RV-C to be examined at the structural level. Among enteroviruses, the only viral genus to have such enzymes, structures were previously reported for 2Apro from RV-A2 [11] and EV-71 [13] determined by crystallography and EV-CB4 [14] determined by NMR. The sequence identities are 57% between A2 and C2, 41% between CB4 and C2, and 40% between EV71 and C2. Structure alignments show that the only relative indels are confined to a short stretch in the first domain (before eI2) and to length discontinuities at the N- and C-terminal cleavage sites (Figure 7). For comparison, important structural and functional elements are highlighted on this map. The substrate-binding di-tyrosine flap (YYP) is marked by an ellipse. The one His (H113) and three Cys residues (C51, C53, C111dashed boxes) responsible for coordinating the structural zinc ion (Figure 5Bgray sphere) converge on the back side of the molecule, basically holding the main domains together. Sequencing studies have highlighted a number of RV isolates that are apparent recombinants within the 2Apro region [42]. When this occurs, invariably, within or between RV-A and RV-C strains, the identified breakpoints cluster in the central linker region and at the C-terminus, swapping the intact N- and C-terminal domains. That these recombinants are apparently fully functional suggests that the two main domains fold independently, with each domain contributing zinc coordination elements that stabilize the full enzyme.

Bottom Line: The catalytic triad consists of conserved Cys (C105), His (H34), and Asp (D18) residues.The backbone of C2 2Apro superimposed closely (1.41-1.81 Å rmsd) with those of orthologs from RV-A2, coxsackie B4 (CB4), and enterovirus 71 (EV71) having sequence identities between 40% and 60%.Comparison of the structures suggest that the differential functional properties of C2 2Apro stem from its unique surface charge, high proportion of surface aromatics, and sequence surrounding the di-tyrosine flap.

View Article: PubMed Central - PubMed

Affiliation: National Magnetic Resonance Facility at Madison, Biochemistry Department, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.

ABSTRACT
Human rhinovirus strains differ greatly in their virulence, and this has been correlated with the differing substrate specificity of the respective 2A protease (2Apro). Rhinoviruses use their 2Apro to cleave a spectrum of cellular proteins important to virus replication and anti-host activities. These enzymes share a chymotrypsin-like fold stabilized by a tetra-coordinated zinc ion. The catalytic triad consists of conserved Cys (C105), His (H34), and Asp (D18) residues. We used a semi-automated NMR protocol developed at NMRFAM to determine the solution structure of 2Apro (C105A variant) from an isolate of the clinically important rhinovirus C species (RV-C). The backbone of C2 2Apro superimposed closely (1.41-1.81 Å rmsd) with those of orthologs from RV-A2, coxsackie B4 (CB4), and enterovirus 71 (EV71) having sequence identities between 40% and 60%. Comparison of the structures suggest that the differential functional properties of C2 2Apro stem from its unique surface charge, high proportion of surface aromatics, and sequence surrounding the di-tyrosine flap.

Show MeSH
Related in: MedlinePlus