Abstract:
The Hox is a group of regulatory genes that produce proteins and direct
pattern formation in the developing embryo. The encoded protein, or the
homeobox, has a segment called the homeodomain which acts as a
transcription factor, binding to other DNA, activating them, and regulating
body pattern formation. Despite great changes in the appearance and
polarity of organisms, these proteins have been known to be highly
conserved throughout evolution. This study employs Bayesian tools to
predict the ancestral structure, function, and sequence of the Hox protein
by using the basal metazoan phyla as sources for any homologous Hox
amino acid sequences that are available from a collaborative online
Knowledge-base. Also, these tools have been used to identify which
present-day sequences are similar to the generated protein. The
reconstructed ancestral sequence has a theoretical pl of 10.01 and a
molecular weight of 15.379.4 Da. It has been found that the Scr protein of
the Drosophila melanogaster is most comparable to the ancestral
sequence. The yeast mating-type protein of Saccharomyces cerevisiae has
also been identified as one of the distant relatives of the generated
sequence, implying the possible primordial functions of the ancestral Hox.
Also, a DNA-binding protein of Arabidopsis thaliana related to auxin
expression Ibr root development regulation has been found to be closely
related to the ancestral Hox. However distant, the protein's structure,
general function, and sequence can be seen to have been relatively
conserved through the course of evolution given its relation to
evolutionarily novel Hox protein sequences.
