Thiaminase

Thiaminase I has the ability to use a multitude of C-N cleaving nucleophilic substrates like cysteine, pyridine, aniline, veratrylamine, dithiothreitol, and quinoline.

Due to this structure scientists proposed that Thiaminase I could have evolved from prehistoric periplasmic binding protein that had been responsible for up taking thiamin.

In order for Thiamin to interact with Thiaminase I it is positioned in the active site between the pyrimidine and Asp272 by two hydrogen bonds.

When viewing Thiaminase II it is found to have a crystal structure that has 11 helices surrounding a deep acidic pocket.

Since thiamine (vitamin B1) is a very important substance required for metabolic pathways by almost all organisms, it can be very detrimental to introduce Thiaminase to a system.

[20] It is also known as the cause of cerebrocortical necrosis of cattle and polioencephalomalasia of sheep eating thiaminase containing plants.

[21][22] It was once causing economical losses in raising fisheries, e.g. in yellowtail fed raw anchovy as a sole feed for a certain period, and also in sea bream and rainbow trout.

[24] In 1860–61, Burke and Wills were the first Europeans to cross Australia south to north; on their return they subsisted primarily on raw nardoo-fern.

The Aborigines prepared nardoo by soaking the sporocarps in water for at least a day to avoid the effects of thiamine deficiency that would result from ingesting the leaves raw.

[2] It is noteworthy to mention that there are several other hypotheses regarding what may have killed Burke and Wills and it is widely disagreed upon by historians and scientists alike.