Sandbox Reserved 828: Difference between revisions
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'''The A protein''' breaks and religates DNA as the DNA cleavage core and the CTD lies on it. | '''The A protein''' breaks and religates DNA as the DNA cleavage core and the CTD lies on it. | ||
The gyrA 59kDa N-ter domain is called Breakage and reunion domain It is composed of two domains at the head region : a winged-helix-turn-helix domain or winged helix domain (WHD) where lies the catalytic tyrosines and a tower domain with alpha/beta structure. | The gyrA 59kDa N-ter domain is called Breakage and reunion domain It is composed of two domains at the head region : a winged-helix-turn-helix domain or winged helix domain (WHD) where lies the catalytic tyrosines and a tower domain with alpha/beta structure. | ||
And a single domain with a helical core at the tail region. Two long helices (a14 anda18) emanate from this core and connect, together with the C-terminal helix (a19), the head and tail fragments. | And a single domain with a helical core at the tail region. Two long helices (a14 anda18) emanate from this core and connect, together with the C-terminal helix (a19), the head and tail fragments. | ||
[[Image:gyrA59.jpg]] | |||
The three connecting helices (a14,a18 anda19) adopt very different conformations, leading to large quaternary movements involving a single hinge-point within the helices and rigid body movements of | The three connecting helices (a14,a18 anda19) adopt very different conformations, leading to large quaternary movements involving a single hinge-point within the helices and rigid body movements of | ||
the head fragments. | the head fragments. | ||
[[Image: | [[Image:helixrot.jpg]] [[Image:gyrA592.jpg]] | ||
The tail is structurally conserved although large surface loops emanating from different points give it a different outward appearance It forms a heart-shaped homodimer with two protein interfaces, the DNA- and C-gates. GyrA59 is the minimal fragment of the A-subunit which, when complexed with the B-subunit, has DNA-cleavage activity. | The tail is structurally conserved although large surface loops emanating from different points give it a different outward appearance It forms a heart-shaped homodimer with two protein interfaces, the DNA- and C-gates. GyrA59 is the minimal fragment of the A-subunit which, when complexed with the B-subunit, has DNA-cleavage activity. | ||
