the proximity of this amino acid to gln-68 which is involved in binding to operator dna ( otwinowski , z. , schevitz , r. w. , zhang , r.-g. , lawson , c. l. , joachimiak , a. , marmorstein , r. q. , luisi , b. f. , and sigler , p. b . ( 1988 ) nature 335 , 321-329 ) may account for this effect .
C0002520
amino acid
C0017797
gln