what is homodomain protein?

Answer 1

The homeodomain fold is a protein structural domain that binds DNA and is thus commonly found in transcription factors. The fold consists of a 60-amino acid helix-turn-helix structurein which three alpha helices are connected by short loop regions. The N-terminal two helices are antiparallel and the longer C-terminal helix is roughly perpendicular to the axes established by the first two. It is this third helix that interacts directly with DNA. Homeodomain folds are found exclusively in eukaryotes but have high homology to lambda phage proteins that alter the expression of genes in prokaryotes. In eukaryotes, homeodomains induce cellular differentiation by initiating the cascades of coregulated genes required to produce individual tissues and organs.

It can also make you homosexual

Answer 2

I believe you meant homeodomain proteins

Homeodomain proteins provide a system with a highly conserved sequence of 60 amino acids spanning across most eukaryotic organisms that fulfill a basic regulatory function. This high degree of conservation makes them an ideal model system for studies attempting to elucidate specific protein-DNA interactions.

The role of these proteins in vivo is to control the genetic determination of developement and implementation of the genetic body plan. This, presumably, is why they are so highly conserved: they fulfill a function too vital to tolerate gross change in sequence or expression pattern. Interestingly, homeotic genes are organized on chromosomes in the same order as the body structure they control, from anterior to posterior.

The general structure of a homeodomain can be described as Helix-Loop-Helix-Turn-Helix, although in Antennapedia the third helix is generally considered to be composed of two helices. One might correctly identify these as Helix-Turn-Helix proteins, although the structure of a homeodomain is more stable and retains its function when isolated.

Specific interactions in Antennapedia, as determined by NMR, reveal most of the features common to homeodomain proteins. They are normally transcription regulators for a wide range of genes; in particular many play a vital role in development and cell differentiation (eg. 1apl). Some are expressed broadly while others are tissue specific.

Answer 3

http://en.wikipedia.org/wiki/Homeodomain_fold

here you go

Answer 4

It's the protein that makes you gay. DUH!