Missing parent: GO:0009975 cyclase activity

[ValWood]

• GO term ID and label for which you request a new superclass

[GO:0009975](https://www.ebi.ac.uk/QuickGO/term/GO:0009975

• New superclass (parent) suggested

Is there any reason why this isn't is) lyase???

• Reference(s), if appropriate
  PMID:nnnnnnn

[pgaudet]

I wonder if that's even a useful term, it doesn't match any high-level ECs. Do we need this?

[ValWood]

Perhaps we don't need it.

However, this class of lyases appear to be mentioned in the definition
Catalysis of the cleavage of C-C, C-O, C-N and other bonds by other means than by hydrolysis or oxidation, or conversely adding a group to a double bond. They differ from other enzymes in that two substrates are involved in one reaction direction, but only one in the other direction. When acting on the single substrate, a molecule is eliminated and this generates either a new double bond or a new ring.

So perhaps they is another EC that covers cyclases with a more chemical description?

PomBase only has 3 cyclases annotated to the 3 highlighted terms
2 are to subclasses (both of which have alternative parents)
and one direct to "cyclase activity" which I could happily move to lyase if you think 'cyclase' is not useful as a grouping term.

However, there are 7 direct EXP annotations to cyclase so there may be some loss of information for these if they cannot be made more specific

[pgaudet]

This is close to the lyase definition pretty:

see https://en.wikipedia.org/wiki/Lyase

lyase is an enzyme that catalyzes the breaking (an elimination reaction) of various chemical bonds by means other than hydrolysis (a substitution reaction) and oxidation, often forming a new double bond or a new ring structure.

Consistent with this, the terms you have above are of EC class 4 (lyase). Seems we should merge these two terms.