Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
In this thesis, an analysis of vertebrate species with chitin synthase (CHS) genes was made. CHS is the enzyme that produces chitin, a long-chain polymer of N-acetylglucosamine subunits. Chitin is the second most abundant polymer in nature, after cellulose. Together with other polysaccharides and proteins, chitin forms composite materials found in many species. Fungi, arthropods (insects & crustaceans) and molluscs are all examples of organisms that produce chitin.
Molluscs has for a long time been considered as the most developed group of organisms with CHS and until recently there wasn't any indications that vertebrates produced chitin.
This analysis shows surprisingly that there are several lower vertebrates, or anamniotes, that have CHS genes, including lamprey (Petromyzon marinus), several bony fishes (Danio rereio, Oryzias latipes, Gasterosteus aculeatus & Gadus morhua) and western clawed frog (Xenopus tropicalis).
A catalytic domain alignment shows a high sequence similarity among the anamniote CHSs, which points to a close relationship to each other. Four out of six motifs important for catalytic function was found in the vertebrate (CHSs, which mean that the enzyme is expressed.
The phylogenetic analysis suggests that tha lower vertebrate CHSs have diverged from a common ancestral enzyme together with fungi, nematode, mollusc, lancelet, insect and tunicate CHSs. Also the domain architecture of the vertebrate CHSs show great similarity with already established CHS genes from e.g. insect CHS. The consluding analysis of synteny in neighbouring genes showed great synteny in between O. latipes & G. aculeatus CHSs.
protein engineering, artificial proteins, α-helix bundles, heme-binding proteins, electron transport