Sandbox Reserved 162: Difference between revisions

This structure of Interleukin-6 was crystallized at 1.9Å. IL-6 is a monomer of 185 amino acids coded by a gene found at locus 7p21 which codes for four introns and five exons. It contains <scene name='Sandbox_Reserved_162/5_helices/2'>five alpha helices</scene>, four of which constitute a classical four-helix bundle with the fifth helix located in the C-D loop. The four helices that form the four-helix bundle are arranged so that two helices (A & B) run parrallel and two (C & D) in an opposing direction. The N-terminal 18 amino acids of IL-6 are not visible in electron density maps and consequently have not been modeled. The first long helix <scene name='Sandbox_Reserved_162/Helix_a/2'>(A)</scene> extends from Ser21 to Ala45 and is connected to a parallel helix (B) by a 25 amino acid loop. This helix <scene name='Sandbox_Reserved_162/Helix_b/1'>(B)</scene> extends from Glu80 to Gln102. A short connection formed from Asn103 to Ser108 joins this helix to the next helix <scene name='Sandbox_Reserved_162/Helix_c/1'>(C)</scene>. This third helix extends from Glu109 to Lys129 and is followed by another amino acid loop which includes a <scene name='Sandbox_Reserved_162/Helix_e/1'>short helix</scene> of three turns (Pro141-Gln152). The last helix <scene name='Sandbox_Reserved_162/Helix_d/2'>(D)</scene> extends from Gln156 to Arg182<ref>Somers W, Stahl M, Seehra J, "1.9Å crystal structure of interleukin 6: implications for a novel mode of receptor dimerization and signaling."  EMBO J, 1997, 16(5), 989-997.</ref>.