BIOB_Ecoli  MAHRPRWTLS QV---TELFE KPL------- --LDLLFEAQ QVHRQH---- ------FDPR QVQVSTLLS- -IKTG-A-CP EDC------- KYC
Mutant      DAHRPRWTLS QVHFNTELFE KPLQTMRQRV PTLDLLFEAQ QVHRQHAKSE EKKHIQFDPR AVQVSTLPSQ NIKTGTAKCP EDCGHKMVLW KYG

            .********* **---***** ***------- --******** ******---- ------**** .******.*- -****-*-** ***------- **.

W = 56 - 4 - 34 = 18.