| Tryptophan synthase is found in the cytoplasm of cells. Here it is able to bind indol-3-glycerol-phosphate and split it into indol and glyceraldehydes-3-phosphate. The location of tryptophan synthase is important because if it wasn't in a part of the cell that had available substrates for it to act on, it would be unable to complete tryptophan synthesis. Tryptophan is an amino acid that is necessary for the production of a variety of proteins. Because it cannot be found and brought into the cell regularly if at all, it must be produced internally. |
| Pectate lyase is generally found outside the cell. This is because the purpose of this enzyme is to cleave glycosidic bonds in cell walls. This enzyme is unique in the three lyases that are being looked at because it does not act on the cell that produces it. Instead, it is used to weaken the barrier of cell walls so that the cell that released the lyase can damage and feed off of the plant cell. This is not always the case though. There is also evidence that pectate lyase plays a role in the softening of fruit as it becomes ripe. |
| Aputinic/apyrimidinic endonuclease is found in the nucleus of the cell. This is fitting because it acts on mismatched DNA strands that are only found in the nucleus. The purpose of this lyase is to cause a nick in the DNA strand so that the mismatched area can be replaced. While it has a very small role in the base excision repair process, it is a key step in the maintenance of DNA. |
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