Editing Protein splicing (section)

==== Split inteins ====
Sometimes, the intein of the precursor protein comes from two genes. In this case, the intein is said to be a ''split intein''. For example, in [[cyanobacteria]], [[DnaE]], the catalytic subunit α of [[DNA polymerase III holoenzyme|DNA polymerase III]], is encoded by two separate genes, ''dnaE-n'' and ''dnaE-c''. The ''dnaE-n'' [[gene product|product]] consists of an N-extein sequence followed by a 123-AA intein sequence, whereas the ''dnaE-c'' product consists of a 36-AA intein sequence followed by a C-extein sequence.<ref name="DnaE">{{Cite journal | doi=10.1073/pnas.95.16.9226 | last1=Wu | first1=H. | last2=Hu | first2=Z. | last3=Liu | first3=X. Q. 
| title=Protein trans-splicing by a split intein encoded in a split DnaE gene of Synechocystis sp. PCC6803 
| journal=Proceedings of the National Academy of Sciences of the United States of America | volume=95 | issue=16 | pages=9226–9231 | year=1998 | pmid=9689062 | pmc=21320| bibcode=1998PNAS...95.9226W | doi-access=free }}</ref>