title: Cysteine biosynthesis and the role of CysE in Neisseria gonorrhoeae

authors: Oldham, Keely

abstract: Neisseria gonorrhoeae is the causative organism of the sexually transmitted infection (STI), gonorrhoea. Over decades of antibiotic use, the emergence of antibiotic-resistant strains of N. gonorrhoeae has dramatically increased and we are facing the reality of almost untreatable gonorrhoea. Combined with increasing incidence, there is an urgent need for new antimicrobial treatments for gonorrhoea infection. The synthesis of the amino acid cysteine is a promising new target for the development of new antimicrobials. Cysteine plays an important role in protein molecules, but also in the synthesis of glutathione for protection against oxidative stress. In addition, cysteine is the key step for the incorporation of sulphur into a variety of cellular constituents. N. gonorrhoeae displays unique differences in assimilation of sulphate for the synthesis of cysteine, yet little is known about the synthesis of this important amino acid in N. gonorrhoeae. 

The first step in the dual-step cysteine biosynthesis pathway is catalysed by the serine acetyltransferase, CysE, an essential gene in N. gonorrhoeae. To design inhibitors against this key enzyme we need to elucidate the enzymatic mechanism and the three-dimensional structure. In this thesis, we determine the kinetic parameters and regulation of CysE and present the structure of CysE to 2.01 Å. Biochemical assays demonstrate that CysE has serine acetyltransferase activity and experiences substrate inhibition by acetyl CoA. CysE is also sensitive to feedback inhibition by L-cysteine, which competitively inhibits CysE relative to the substrate L-serine. The structure shows CysE belongs to the left-handed β helix family and adopts a hexameric structure consisting of a dimer of trimers. Our structure reveals the first evidence of domain swapping for a CysE structure, where C-terminal tails domain swap with neighbouring monomers in the crystal lattice. Although an artefact of crystallisation it provides insight into the flexibility of this region. 

Collectively the data presented in this thesis represents key advances in our understanding of the uncharacterised cysteine biosynthetic pathway in N. gonorrhoeae. Data presented here is the basis for future work using the structure of CysE to guide computational inhibitor design, to identify lead compounds for CysE inhibition, and for the development of new antimicrobials for treatment of gonorrhoea.

text: Cysteine biosynthesis and the role of CysE in Neisseria gonorrhoeae Neisseria gonorrhoeae is the causative organism of the sexually transmitted infection (STI), gonorrhoea. Over decades of antibiotic use, the emergence of antibiotic-resistant strains of N. gonorrhoeae has dramatically increased and we are facing the reality of almost untreatable gonorrhoea. Combined with increasing incidence, there is an urgent need for new antimicrobial treatments for gonorrhoea infection. The synthesis of the amino acid cysteine is a promising new target for the development of new antimicrobials. Cysteine plays an important role in protein molecules, but also in the synthesis of glutathione for protection against oxidative stress. In addition, cysteine is the key step for the incorporation of sulphur into a variety of cellular constituents. N. gonorrhoeae displays unique differences in assimilation of sulphate for the synthesis of cysteine, yet little is known about the synthesis of this important amino acid in N. gonorrhoeae. 

The first step in the dual-step cysteine biosynthesis pathway is catalysed by the serine acetyltransferase, CysE, an essential gene in N. gonorrhoeae. To design inhibitors against this key enzyme we need to elucidate the enzymatic mechanism and the three-dimensional structure. In this thesis, we determine the kinetic parameters and regulation of CysE and present the structure of CysE to 2.01 Å. Biochemical assays demonstrate that CysE has serine acetyltransferase activity and experiences substrate inhibition by acetyl CoA. CysE is also sensitive to feedback inhibition by L-cysteine, which competitively inhibits CysE relative to the substrate L-serine. The structure shows CysE belongs to the left-handed β helix family and adopts a hexameric structure consisting of a dimer of trimers. Our structure reveals the first evidence of domain swapping for a CysE structure, where C-terminal tails domain swap with neighbouring monomers in the crystal lattice. Although an artefact of crystallisation it provides insight into the flexibility of this region. 

Collectively the data presented in this thesis represents key advances in our understanding of the uncharacterised cysteine biosynthetic pathway in N. gonorrhoeae. Data presented here is the basis for future work using the structure of CysE to guide computational inhibitor design, to identify lead compounds for CysE inhibition, and for the development of new antimicrobials for treatment of gonorrhoea.

year: 2020

title: Innovation, R&D cooperation and labor recruitment: evidence from Finland

authors: Simonen, Jaakko

subjects: innovation

abstract: This article investigates the role played by one type of firm interaction, namely R&D cooperation, and also the acquisition of labor, in the promotion of industrial innovations. We employ a unique innovation dataset from Finland which combines firm specific information about the innovation performance of the firms along with their individual characteristics, as well as firm specific information regarding the origins of their recent labor acquisitions. Analyzing this data allows us to identify the different roles which the knowledge spillovers and labor markets play in the innovation process. Our results suggest that small firms are generally more innovative than large firms; R&D cooperation is an essential feature of innovation, but the variety of cooperation is of little importance; and labor acquisition appears to be only of limited importance for innovation.

text: Innovation, R&D cooperation and labor recruitment: evidence from Finland This article investigates the role played by one type of firm interaction, namely R&D cooperation, and also the acquisition of labor, in the promotion of industrial innovations. We employ a unique innovation dataset from Finland which combines firm specific information about the innovation performance of the firms along with their individual characteristics, as well as firm specific information regarding the origins of their recent labor acquisitions. Analyzing this data allows us to identify the different roles which the knowledge spillovers and labor markets play in the innovation process. Our results suggest that small firms are generally more innovative than large firms; R&D cooperation is an essential feature of innovation, but the variety of cooperation is of little importance; and labor acquisition appears to be only of limited importance for innovation.

year: 2008

title: HE PI KA RERE 'An Early Childhood Approach to a Cultural Milieu'

authors: Karu, Joceleen Helen

subjects: Early childhood education

abstract: This study explores the issues surrounding the inculcation of te reo me ngā tikanga Māori, Māori language customs and values among early childhood teacher educators in a tertiary setting and how these academics go about preparing students with limited or sufficient knowledge of te reo Māori (Māori language) me ngā tikanga Māori (Māori cultural practices) to meet expectations. Te Whāriki, the early childhood curriculum is a curriculum commonly referred to as a bicultural curriculum that contains two expressions of the curriculum, one for general early childhood centres and another for kōhanga reo, neither of which are translations of one another and further asserts the importance of Te Tiriti o Waitangi/ the Treaty of Waitangi and the responsibility of teachers for bicultural development in the education of all children. Equally important, Te Whāriki acknowledges the dual heritage existent within Aotearoa/ New Zealand and further encourages teachers in early childhood settings to have knowledge of te reo and tikanga Māori. Policy imperatives reflected within the New Zealand Graduating Teaching Standards (New Zealand Teachers Council, 2010) and the Ministry of Education’s document Tātaiako/ Cultural Competencies (2011) place further emphasis on the need for those in initial teacher education to demonstrate their conversancy with te reo me ngā tikanga Māori.
The purpose of this study is to provide a narrative of the ways in which the early childhood initial teacher education programme prepares students to use te reo and tikanga Māori. It offers a premise to engage in further discussion of the continued effectiveness of early childhood teacher educators in the maintenance and delivery of te reo me ngā tikanga Māori and sets in motion a cyclical platform for further research from a traditional worldview which reflects and embodies the Māori language, culture and identity through a Kaupapa Māori philosophy and praxis.

text: HE PI KA RERE 'An Early Childhood Approach to a Cultural Milieu' This study explores the issues surrounding the inculcation of te reo me ngā tikanga Māori, Māori language customs and values among early childhood teacher educators in a tertiary setting and how these academics go about preparing students with limited or sufficient knowledge of te reo Māori (Māori language) me ngā tikanga Māori (Māori cultural practices) to meet expectations. Te Whāriki, the early childhood curriculum is a curriculum commonly referred to as a bicultural curriculum that contains two expressions of the curriculum, one for general early childhood centres and another for kōhanga reo, neither of which are translations of one another and further asserts the importance of Te Tiriti o Waitangi/ the Treaty of Waitangi and the responsibility of teachers for bicultural development in the education of all children. Equally important, Te Whāriki acknowledges the dual heritage existent within Aotearoa/ New Zealand and further encourages teachers in early childhood settings to have knowledge of te reo and tikanga Māori. Policy imperatives reflected within the New Zealand Graduating Teaching Standards (New Zealand Teachers Council, 2010) and the Ministry of Education’s document Tātaiako/ Cultural Competencies (2011) place further emphasis on the need for those in initial teacher education to demonstrate their conversancy with te reo me ngā tikanga Māori.
The purpose of this study is to provide a narrative of the ways in which the early childhood initial teacher education programme prepares students to use te reo and tikanga Māori. It offers a premise to engage in further discussion of the continued effectiveness of early childhood teacher educators in the maintenance and delivery of te reo me ngā tikanga Māori and sets in motion a cyclical platform for further research from a traditional worldview which reflects and embodies the Māori language, culture and identity through a Kaupapa Māori philosophy and praxis.

year: 2015