Perhaps due to outer coat protein individually or collectively.


closed as unclear what you're asking by MattDMo, AliceD, rg255, James, WYSIWYG Apr 19 '16 at 9:14

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    $\begingroup$ Yes even the smallest viruses have enzymes. like reverse transcriptase/integrase in retroviruses. Your question is unclear. $\endgroup$ – WYSIWYG Apr 17 '16 at 10:16
  • $\begingroup$ I think he's talking about the intact virus particle. I suspect the answer is no, as the initial aim of the virus particle on infection is to get into the cell, and until it does that substrates will be thin on the ground. But Nature's always full of weird oddities, so who knows? $\endgroup$ – David Apr 17 '16 at 19:16
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    $\begingroup$ @David Influenza virus, for example, has neuraminidase on its coat. $\endgroup$ – WYSIWYG Apr 18 '16 at 5:38
  • $\begingroup$ @WYSWYG Not even weird. I'd forgotten that the virus particle needs to get out of the cell as well as get in (which I gather is the function of neuramidase). $\endgroup$ – David Apr 18 '16 at 8:52
  • $\begingroup$ @WYSIWYG I add a chemical with virus particles, without the help of cellular machinery will the virus be able to transform the chemical? Are there such virus? That was the question. You have answered affirmative with an example. Thanks. Is this common? $\endgroup$ – Ahmed Abdullah Apr 18 '16 at 9:07

As some of the comments mention, this question could use some clarification.

First, assuming you're asking in general about enzymatic activity in viruses:

A few classes of "non-autonomous" viruses (particularly endogenous retrotransposons) don't encode any enzymatic functions and sometimes don't even encode their own structural proteins - they rely on the structural proteins and/or enzymatic functions of the "autonomous" viruses.

With the exception of those non-autonomous viruses, all retroviruses encode the reverse transcriptase and integrase functions, while many non-retroviruses (those which don't have a step in their lifecycle where they convert RNA into DNA) also have RNA-dependent RNA polymerase activities.

Now, assuming you meant to limit your question to the viral coat (AKA capsid) proteins of an intact virus-like particle (VLP):

Most do not have any "enzymatic" activity per se - they do not catalyze the formation or breakage of any covalent bonds. However, many viral coat proteins have membrane associated domains which undergo conformational changes essential for uncoating and trafficking of the virus across the membrane:

Gao, D., Lin, X., Zhang, Z., Li, W., Men, D., Zhang, X., & Cui, Z. (2016). Original Article: Intracellular cargo delivery by virus capsid protein-based vehicles: From nano to micro. Nanomedicine: Nanotechnology, Biology, And Medicine, 12365-376. doi:10.1016/j.nano.2015.10.023

This membrane translocating (aka cell penetrating) activity sometimes does depend on the "collective" action of oligomeric complexes of capsid proteins, but it is not an enzymatic activity.

However, the parvoviruses do encode a phospholipase enzymatic activity in their coat proteins which serves to disrupt cellular membranes and allow viral entry:

Kobiler, O., Drayman, N., Butin-Israeli, V., & Oppenheim, A. (n.d). Virus strategies for passing the nuclear envelope barrier. Nucleus-Austin, 3(6), 526-539.

I don't know of any other classes of coat proteins with bona fide enzymatic activity, but I wouldn't be surprised if some exist, and I've only touched on a few of the multitude of enzymatic activities exhibited by other viral components.

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    $\begingroup$ There are other examples of enzymatic activity in the capsid such as the neuraminidase of influenza virus. $\endgroup$ – WYSIWYG Apr 18 '16 at 5:33

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