This work investigates the isoprenyl diphosphate synthase Rv2173 of Mycobacterium tuberculosis through elucidation and analysis of three 2.0-2.2 Å resolution structures; APO and two substrate bound forms with isopentenyl diphosphate and dimethylallyl diphosphate. This is supported by examination of the oligomeric state of Rv2173 via native mass spectrometry, size exclusion chromatography, small angle x-ray scattering and other methods. Analysis reveals a canonical all alpha-helical trans-isoprenyl diphosphate synthase fold that is dimeric for each form and aligns with literature predictions as to the expected product determination pathway of similar Mycobacterium tuberculosis isoprenyl diphosphate synthases. Additionally, this work investigates the glycosyltransferases of the Campylobacter jejuni N-linked glycosylation pathway, PglC, PglA and PglJ respectively. This is achieved through optimisation of the expression constructs, bacterial systems and purification methodology for each protein, supported by mass spectrometry, detergent analysis and circular dichorism. Exhaustive crystallisation trials of these glycosyltransferases were attempted across a range of commercial and bespoke conditions which provides a primer for promising formulations that can be trialled further. Where experimentally-determined structures were unavailable for analysis, in silico prediction models have been used to estimate hypothetical tertiary structure organisations. Understanding the hypothetical nature of these reviews, a discussion on the validity and state-of-the-art in regards to in silico modelling is also considered.