{"id":{"repo_id":"nus","oai_identifier":"oai:scholarbank.nus.edu.sg:10635/27784"},"canonical_url":"https://search.dev.ndltd.org/etd/nus/oai:scholarbank.nus.edu.sg:10635/27784","repository":{"repo_id":"nus","name":"National University of Singapore","base_url":"https://scholarbank.nus.edu.sg/oai/request"},"display":{"title":"Microbiology of periodontal disease in Singapore and the discovery of a bacterial intron in Actinobacillus actinomycetemcomitans","abstract":"Ethnicity is a risk factor for periodontal disease. The occurrence of major periodontal pathogens in a total of 410 periodontally healthy and diseased subjects in the ethnic Chinese in Singapore were determined. Actinobacillus actinomycetemcomitans cdt; Porphyromonas gingivalis prtC and Tannerella forsythensis (Bacteroides forsythus) prtH genotypes correlated well with the periodontal status of the local population. A. actinomycetemcomitans possesses the cytolethal-distending toxin (CDT). The 2.1 kb cdt gene gave three reverse transcription-polymerase chain reaction (RT-PCR) bands of 2.1 kb, 1.5 kb and 0.9 kb. Recombinant E. coli possessing the cdt gene gave similar results. In vitro transcribed cdt RNA catalyzed its own excision. The spliced products possessed different 5a?? exons but shared the same 3a?? exon with ribosome-binding site present upstream. Conservation of splice-site consensus sequence was important for accurate splicing. The a??catalytic corea?? was a 0.56 kb RNA segment located within the 2.1 kb precursor RNA, capable of splicing heterologous RNA in the cis and trans configuration.","abstract_html":"Ethnicity is a risk factor for periodontal disease. The occurrence of major periodontal pathogens in a total of 410 periodontally healthy and diseased subjects in the ethnic Chinese in Singapore were determined. Actinobacillus actinomycetemcomitans cdt; Porphyromonas gingivalis prtC and Tannerella forsythensis (Bacteroides forsythus) prtH genotypes correlated well with the periodontal status of the local population. A. actinomycetemcomitans possesses the cytolethal-distending toxin (CDT). The 2.1 kb cdt gene gave three reverse transcription-polymerase chain reaction (RT-PCR) bands of 2.1 kb, 1.5 kb and 0.9 kb. Recombinant E. coli possessing the cdt gene gave similar results. In vitro transcribed cdt RNA catalyzed its own excision. The spliced products possessed different 5a?? exons but shared the same 3a?? exon with ribosome-binding site present upstream. Conservation of splice-site consensus sequence was important for accurate splicing. The a??catalytic corea?? was a 0.56 kb RNA segment located within the 2.1 kb precursor RNA, capable of splicing heterologous RNA in the cis and trans configuration.","abstract_has_math":false,"creators":["TAN KAI SOO"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2004,"date_issued":"2004-10-06","date_published":"2004-10-06","updated_at":"2026-07-24T03:33:22Z","subjects":["Periodontal disease, Actinobacillus actinomycetemcomitans, Ethnicity, cytolethal-distending toxin, bacterial intron, catalytic RNA"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["TAN KAI SOO"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2004-10-06"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://scholarbank.nus.edu.sg/handle/10635/27784"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Periodontal disease, Actinobacillus actinomycetemcomitans, Ethnicity, cytolethal-distending toxin, bacterial intron, catalytic RNA"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://scholarbank.nus.edu.sg/bitstreams/bf75487c-f7ac-4975-9e89-4b09540f59ea/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Ethnicity is a risk factor for periodontal disease. The occurrence of major periodontal pathogens in a total of 410 periodontally healthy and diseased subjects in the ethnic Chinese in Singapore were determined. Actinobacillus actinomycetemcomitans cdt; Porphyromonas gingivalis prtC and Tannerella forsythensis (Bacteroides forsythus) prtH genotypes correlated well with the periodontal status of the local population. A. actinomycetemcomitans possesses the cytolethal-distending toxin (CDT). The 2.1 kb cdt gene gave three reverse transcription-polymerase chain reaction (RT-PCR) bands of 2.1 kb, 1.5 kb and 0.9 kb. Recombinant E. coli possessing the cdt gene gave similar results. In vitro transcribed cdt RNA catalyzed its own excision. The spliced products possessed different 5a?? exons but shared the same 3a?? exon with ribosome-binding site present upstream. Conservation of splice-site consensus sequence was important for accurate splicing. The a??catalytic corea?? was a 0.56 kb RNA segment located within the 2.1 kb precursor RNA, capable of splicing heterologous RNA in the cis and trans configuration."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["b277326460681d00461779a8666b2ece","29ad37c6db0dec43fa538ffb56ae498f"]},{"key":"dc:title","label":"Title","values":["Microbiology of periodontal disease in Singapore and the discovery of a bacterial intron in Actinobacillus actinomycetemcomitans"]}]}],"canonical_facts":{"dc:creator":["TAN KAI SOO"],"dc:date.issued":["2004-10-06"],"dc:description.abstract":["Ethnicity is a risk factor for periodontal disease. The occurrence of major periodontal pathogens in a total of 410 periodontally healthy and diseased subjects in the ethnic Chinese in Singapore were determined. Actinobacillus actinomycetemcomitans cdt; Porphyromonas gingivalis prtC and Tannerella forsythensis (Bacteroides forsythus) prtH genotypes correlated well with the periodontal status of the local population. A. actinomycetemcomitans possesses the cytolethal-distending toxin (CDT). The 2.1 kb cdt gene gave three reverse transcription-polymerase chain reaction (RT-PCR) bands of 2.1 kb, 1.5 kb and 0.9 kb. Recombinant E. coli possessing the cdt gene gave similar results. In vitro transcribed cdt RNA catalyzed its own excision. The spliced products possessed different 5a?? exons but shared the same 3a?? exon with ribosome-binding site present upstream. Conservation of splice-site consensus sequence was important for accurate splicing. The a??catalytic corea?? was a 0.56 kb RNA segment located within the 2.1 kb precursor RNA, capable of splicing heterologous RNA in the cis and trans configuration."],"dc:format.checksum.md5":["b277326460681d00461779a8666b2ece","29ad37c6db0dec43fa538ffb56ae498f"],"dc:identifier.uri":["https://scholarbank.nus.edu.sg/bitstreams/bf75487c-f7ac-4975-9e89-4b09540f59ea/download"],"dc:relation.isreferencedby":["https://scholarbank.nus.edu.sg/handle/10635/27784"],"dc:subject":["Periodontal disease, Actinobacillus actinomycetemcomitans, Ethnicity, cytolethal-distending toxin, bacterial intron, catalytic RNA"],"dc:title":["Microbiology of periodontal disease in Singapore and the discovery of a bacterial intron in Actinobacillus actinomycetemcomitans"],"dc:type":["Thesis"]},"updated_at":"2026-07-24T03:33:22Z"}