Crystal structures of Aspergillus oryzae Rib2 deaminase: the functional mechanism involved in riboflavin biosynthesis
Riboflavin serves as the direct precursor of the FAD/FMN coenzymes and is biosynthesized in most prokaryotes, fungi and plants. Fungal Rib2 possesses a deaminase domain for deamination of pyrimidine in the third step of riboflavin biosynthesis. Here, four high-resolution crystal structures of a Rib2...
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International Union of Crystallography
2021-07-01
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| Series: | IUCrJ |
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| Online Access: | http://scripts.iucr.org/cgi-bin/paper?S205225252100275X |
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| author | Sheng-Chia Chen Li-Ci Ye Te-Ming Yen Ruei-Xin Zhu Cheng-Yu Li San-Chi Chang Shwu-Huey Liaw Chun-Hua Hsu |
| author_facet | Sheng-Chia Chen Li-Ci Ye Te-Ming Yen Ruei-Xin Zhu Cheng-Yu Li San-Chi Chang Shwu-Huey Liaw Chun-Hua Hsu |
| author_sort | Sheng-Chia Chen |
| collection | DOAJ |
| description | Riboflavin serves as the direct precursor of the FAD/FMN coenzymes and is biosynthesized in most prokaryotes, fungi and plants. Fungal Rib2 possesses a deaminase domain for deamination of pyrimidine in the third step of riboflavin biosynthesis. Here, four high-resolution crystal structures of a Rib2 deaminase from Aspergillus oryzae (AoRib2) are reported which display three distinct occluded, open and complex forms that are involved in substrate binding and catalysis. In addition to the deaminase domain, AoRib2 contains a unique C-terminal segment which is rich in charged residues. Deletion of this unique segment has no effect on either enzyme activity or protein stability. Nevertheless, the C-terminal αF helix preceding the segment plays a role in maintaining protein stability and activity. Unexpectedly, AoRib2 is the first mononucleotide deaminase found to exist as a monomer, perhaps due to the assistance of its unique longer loops (Lβ1–β2, LαB–β3 and LαC–β4). These results form the basis for a molecular understanding of riboflavin biosynthesis in fungi and might assist in the development of antibiotics. |
| first_indexed | 2024-04-11T16:38:39Z |
| format | Article |
| id | doaj.art-bd533ed7190a49f39d8aafdee0c88432 |
| institution | Directory Open Access Journal |
| issn | 2052-2525 |
| language | English |
| last_indexed | 2024-04-11T16:38:39Z |
| publishDate | 2021-07-01 |
| publisher | International Union of Crystallography |
| record_format | Article |
| series | IUCrJ |
| spelling | doaj.art-bd533ed7190a49f39d8aafdee0c884322022-12-22T04:13:45ZengInternational Union of CrystallographyIUCrJ2052-25252021-07-018454955810.1107/S205225252100275Xlz5048Crystal structures of Aspergillus oryzae Rib2 deaminase: the functional mechanism involved in riboflavin biosynthesisSheng-Chia Chen0Li-Ci Ye1Te-Ming Yen2Ruei-Xin Zhu3Cheng-Yu Li4San-Chi Chang5Shwu-Huey Liaw6Chun-Hua Hsu7Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 11221, TaiwanDepartment of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 11221, TaiwanInstitute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 11217, TaiwanDepartment of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 11221, TaiwanDepartment of Chemistry, National Taiwan University, Taipei 10617, TaiwanDepartment of Agricultural Chemistry, National Taiwan University, Taipei 10617, TaiwanDepartment of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 11221, TaiwanDepartment of Agricultural Chemistry, National Taiwan University, Taipei 10617, TaiwanRiboflavin serves as the direct precursor of the FAD/FMN coenzymes and is biosynthesized in most prokaryotes, fungi and plants. Fungal Rib2 possesses a deaminase domain for deamination of pyrimidine in the third step of riboflavin biosynthesis. Here, four high-resolution crystal structures of a Rib2 deaminase from Aspergillus oryzae (AoRib2) are reported which display three distinct occluded, open and complex forms that are involved in substrate binding and catalysis. In addition to the deaminase domain, AoRib2 contains a unique C-terminal segment which is rich in charged residues. Deletion of this unique segment has no effect on either enzyme activity or protein stability. Nevertheless, the C-terminal αF helix preceding the segment plays a role in maintaining protein stability and activity. Unexpectedly, AoRib2 is the first mononucleotide deaminase found to exist as a monomer, perhaps due to the assistance of its unique longer loops (Lβ1–β2, LαB–β3 and LαC–β4). These results form the basis for a molecular understanding of riboflavin biosynthesis in fungi and might assist in the development of antibiotics.http://scripts.iucr.org/cgi-bin/paper?S205225252100275Xriboflavin biosynthesisrib2deaminasessubstrate bindingcrystal structure |
| spellingShingle | Sheng-Chia Chen Li-Ci Ye Te-Ming Yen Ruei-Xin Zhu Cheng-Yu Li San-Chi Chang Shwu-Huey Liaw Chun-Hua Hsu Crystal structures of Aspergillus oryzae Rib2 deaminase: the functional mechanism involved in riboflavin biosynthesis IUCrJ riboflavin biosynthesis rib2 deaminases substrate binding crystal structure |
| title | Crystal structures of Aspergillus oryzae Rib2 deaminase: the functional mechanism involved in riboflavin biosynthesis |
| title_full | Crystal structures of Aspergillus oryzae Rib2 deaminase: the functional mechanism involved in riboflavin biosynthesis |
| title_fullStr | Crystal structures of Aspergillus oryzae Rib2 deaminase: the functional mechanism involved in riboflavin biosynthesis |
| title_full_unstemmed | Crystal structures of Aspergillus oryzae Rib2 deaminase: the functional mechanism involved in riboflavin biosynthesis |
| title_short | Crystal structures of Aspergillus oryzae Rib2 deaminase: the functional mechanism involved in riboflavin biosynthesis |
| title_sort | crystal structures of aspergillus oryzae rib2 deaminase the functional mechanism involved in riboflavin biosynthesis |
| topic | riboflavin biosynthesis rib2 deaminases substrate binding crystal structure |
| url | http://scripts.iucr.org/cgi-bin/paper?S205225252100275X |
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