US6933362 How could a researcher use the sequence of this intein molecule to synthesize it now for scientific and research purpose? Is this patent still active?
I can't speak to your first question, but can help with your question regarding whether the patent is still active.
The patent application was filed on August 17, 2000, claims priority to a provisional application filed on August 17, 1999 and issued on August 23, 2005.
US patents issuing from patent applications filed on or after June 8, 1995 have a term of 20 years from the earliest non-provisional patent application priority date. US patents issuing from patent applications filed prior to June 8, 1995 have a term equal to the greater of 17 years from issuance or 20 years from the earliest non-provisional patent application priority date.
In this case, the term is 20 years from the filing date of August 17, 2000 and (assuming all maintenance fees are paid) the patent will expire on August 17, 2020.