Hox gene is an example of a homeobox gene. The homeobox sequence codes for a 60 amino acid protein domain known as the homeodomain. The main role of homeodomain is to act as a switch that controls gene transcription. See also: Hox gene.
Guanine /ËÉ¡wÉËnÉ¨n/ (G, Gua) is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine (uracil in RNA). In DNA, guanine is paired with cytosine. With the formula C 5 H 5 N 5 O, guanine is a derivative of purine, consisting of a fused pyrimidine-imidazole ring system with conjugated double bonds. Being unsaturated, the bicyclic molecule is planar. The guanine nucleoside is called guanosine.
Guanine [edit]. Guanine base. The NH group is bonded to the sugar within the nucleotide, and the other groups participate in hydrogen bonding to cytosine. Guanine is among the five nucleobases that is found in DNA and RNA. The formula of guanine is C 5 H 5 N 5 O, and is a planar and bicyclic molecule. Guanine has two forms, keto and enol forms. The keto form is the major form. Guanine, like adenine, is a derivative of purine and binds to cytosine through 3 hydrogen bonds. The amino group in the cytosine is the hydrogen donor and the C2 carbonyl and the N3 amine are the hydrogen-bond acceptors.