@article{jin_zhang_zhang_nguyen_lindsey_miller_2021, title={Identification of Putative Biosynthetic Gene Clusters for Tolyporphins in Multiple Filamentous Cyanobacteria}, volume={11}, ISSN={["2075-1729"]}, DOI={10.3390/life11080758}, abstractNote={Tolyporphins A–R are unusual tetrapyrrole macrocycles produced by the non-axenic filamentous cyanobacterium HT-58-2. A putative biosynthetic gene cluster for biosynthesis of tolyporphins (here termed BGC-1) was previously identified in the genome of HT-58-2. Here, homology searching of BGC-1 in HT-58-2 led to identification of similar BGCs in seven other filamentous cyanobacteria, including strains Nostoc sp. 106C, Nostoc sp. RF31YmG, Nostoc sp. FACHB-892, Brasilonema octagenarum UFV-OR1, Brasilonema octagenarum UFV-E1, Brasilonema sennae CENA114 and Oculatella sp. LEGE 06141, suggesting their potential for tolyporphins production. A similar gene cluster (BGC-2) also was identified unexpectedly in HT-58-2. Tolyporphins BGCs were not identified in unicellular cyanobacteria. Phylogenetic analysis based on 16S rRNA and a common component of the BGCs, TolD, points to a close evolutionary history between each strain and their respective tolyporphins BGC. Though identified with putative tolyporphins BGCs, examination of pigments extracted from three cyanobacteria has not revealed the presence of tolyporphins. Overall, the identification of BGCs and potential producers of tolyporphins presents a collection of candidate cyanobacteria for genetic and biochemical analysis pertaining to these unusual tetrapyrrole macrocycles.}, number={8}, journal={LIFE-BASEL}, author={Jin, Xiaohe and Zhang, Yunlong and Zhang, Ran and Nguyen, Kathy-Uyen and Lindsey, Jonathan S. and Miller, Eric S.}, year={2021}, month={Aug} }
 @article{jin_miller_lindsey_2021, title={Natural Product Gene Clusters in the Filamentous Nostocales Cyanobacterium HT-58-2}, volume={11}, ISSN={["2075-1729"]}, DOI={10.3390/life11040356}, abstractNote={Cyanobacteria are known as rich repositories of natural products. One cyanobacterial-microbial consortium (isolate HT-58-2) is known to produce two fundamentally new classes of natural products: the tetrapyrrole pigments tolyporphins A–R, and the diterpenoid compounds tolypodiol, 6-deoxytolypodiol, and 11-hydroxytolypodiol. The genome (7.85 Mbp) of the Nostocales cyanobacterium HT-58-2 was annotated previously for tetrapyrrole biosynthesis genes, which led to the identification of a putative biosynthetic gene cluster (BGC) for tolyporphins. Here, bioinformatics tools have been employed to annotate the genome more broadly in an effort to identify pathways for the biosynthesis of tolypodiols as well as other natural products. A putative BGC (15 genes) for tolypodiols has been identified. Four BGCs have been identified for the biosynthesis of other natural products. Two BGCs related to nitrogen fixation may be relevant, given the association of nitrogen stress with production of tolyporphins. The results point to the rich biosynthetic capacity of the HT-58-2 cyanobacterium beyond the production of tolyporphins and tolypodiols.}, number={4}, journal={LIFE-BASEL}, author={Jin, Xiaohe and Miller, Eric S. and Lindsey, Jonathan S.}, year={2021}, month={Apr} }
 @article{hughes_jin_zhang_zhang_tran_williams_lindsey_miller_2018, title={Genome sequence, metabolic properties and cyanobacterial attachment of Porphyrobacter sp. HT-58-2 isolated from a filamentous cyanobacterium–microbial consortium}, volume={164}, ISSN={1350-0872 1465-2080}, url={http://dx.doi.org/10.1099/mic.0.000706}, DOI={10.1099/mic.0.000706}, abstractNote={Tolyporphins are structurally diverse tetrapyrrole macrocycles produced by the cyanobacterial culture HT-58-2. Although tolyporphins were discovered over 25 years ago, little was known about the microbiology of the culture. The studies reported herein expand the description of the community of predominantly alphaproteobacteria associated with the filamentous HT-58-2 cyanobacterium and isolate a dominant bacterium, Porphyrobacter sp. HT-58-2, for which the complete genome is established and growth properties are examined. Fluorescence in situ hybridization (FISH) analysis of the cyanobacterium-microbial community with a probe targeting the 16S rRNA of Porphyrobacter sp. HT-58-2 showed fluorescence emanating from the cyanobacterial sheath. Although genes for the biosynthesis of bacteriochlorophyll a (BChl a) are present in the Porphyrobacter sp. HT-58-2 genome, the pigment was not detected under the conditions examined, implying the absence of phototrophic growth. Comparative analysis of four Porphyrobacter spp. genomes from worldwide collection sites showed significant collinear gene blocks, with two inversions and three deletion regions. Taken together, the results enrich our understanding of the HT-58-2 cyanobacterium-microbial culture.}, number={10}, journal={Microbiology}, publisher={Microbiology Society}, author={Hughes, Rebecca-Ayme and Jin, Xiaohe and Zhang, Yunlong and Zhang, Ran and Tran, Sabrina and Williams, Philip G. and Lindsey, Jonathan S. and Miller, Eric S.}, year={2018}, month={Oct}, pages={1229–1239} }