Mutational Pathways and Trade-Offs Between HisA and TrpF Functions: Implications for Evolution via Gene Duplication and Divergence
When a new activity evolves by changes in a pre-existing enzyme this is likely to reduce the original activity, generating a functional trade-off. The properties of this trade-off will affect the continued evolution of both functions. If the trade-off is strong, gene duplication and subsequent diver...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2020-10-01
|
| Series: | Frontiers in Microbiology |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/article/10.3389/fmicb.2020.588235/full |
| _version_ | 1819228086977167360 |
|---|---|
| author | Erik Lundin Joakim Näsvall Dan I. Andersson |
| author_facet | Erik Lundin Joakim Näsvall Dan I. Andersson |
| author_sort | Erik Lundin |
| collection | DOAJ |
| description | When a new activity evolves by changes in a pre-existing enzyme this is likely to reduce the original activity, generating a functional trade-off. The properties of this trade-off will affect the continued evolution of both functions. If the trade-off is strong, gene duplication and subsequent divergence would be favored whereas if the trade-off is weak a bi-functional enzyme could evolve that performs both functions. We previously showed that when a bi-functional HisA enzyme was evolved under selection for both HisA and TrpF functions, evolution mainly proceeded via duplication-divergence and specialization, implying that the trade-off is strong between these two functions. Here, we examined this hypothesis by identifying the mutational pathways (i.e., the mutational landscape) in the Salmonella enterica HisA enzyme that conferred a TrpF-like activity, and examining the trade-offs between the original and new activity. For the HisA enzyme there are many different paths toward the new TrpF function, each with its own unique trade-off. A total of 16 single mutations resulted in HisA enzyme variants that acquired TrpF activity and only three of them maintained HisA activity. Twelve mutants were evolved further toward increased TrpF activity and during evolution toward improved TrpF activity the original HisA activity was completely lost in all lineages. We propose that, aside from various relevant ecological factors, two main genetic factors influence whether evolution of a new function proceeds via duplication – divergence (specialization) or by evolution of a generalist: (i) the relative mutation supply of the two pathways and (ii) the shape of the trade-off curve between the native and new function. |
| first_indexed | 2024-12-23T10:51:42Z |
| format | Article |
| id | doaj.art-e545a50af4d64a17958899625dd27593 |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-12-23T10:51:42Z |
| publishDate | 2020-10-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-e545a50af4d64a17958899625dd275932022-12-21T17:49:53ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2020-10-011110.3389/fmicb.2020.588235588235Mutational Pathways and Trade-Offs Between HisA and TrpF Functions: Implications for Evolution via Gene Duplication and DivergenceErik LundinJoakim NäsvallDan I. AnderssonWhen a new activity evolves by changes in a pre-existing enzyme this is likely to reduce the original activity, generating a functional trade-off. The properties of this trade-off will affect the continued evolution of both functions. If the trade-off is strong, gene duplication and subsequent divergence would be favored whereas if the trade-off is weak a bi-functional enzyme could evolve that performs both functions. We previously showed that when a bi-functional HisA enzyme was evolved under selection for both HisA and TrpF functions, evolution mainly proceeded via duplication-divergence and specialization, implying that the trade-off is strong between these two functions. Here, we examined this hypothesis by identifying the mutational pathways (i.e., the mutational landscape) in the Salmonella enterica HisA enzyme that conferred a TrpF-like activity, and examining the trade-offs between the original and new activity. For the HisA enzyme there are many different paths toward the new TrpF function, each with its own unique trade-off. A total of 16 single mutations resulted in HisA enzyme variants that acquired TrpF activity and only three of them maintained HisA activity. Twelve mutants were evolved further toward increased TrpF activity and during evolution toward improved TrpF activity the original HisA activity was completely lost in all lineages. We propose that, aside from various relevant ecological factors, two main genetic factors influence whether evolution of a new function proceeds via duplication – divergence (specialization) or by evolution of a generalist: (i) the relative mutation supply of the two pathways and (ii) the shape of the trade-off curve between the native and new function.https://www.frontiersin.org/article/10.3389/fmicb.2020.588235/fullduplicationdivergencetrade-offHISATrpFSalmonella enterica |
| spellingShingle | Erik Lundin Joakim Näsvall Dan I. Andersson Mutational Pathways and Trade-Offs Between HisA and TrpF Functions: Implications for Evolution via Gene Duplication and Divergence Frontiers in Microbiology duplication divergence trade-off HISA TrpF Salmonella enterica |
| title | Mutational Pathways and Trade-Offs Between HisA and TrpF Functions: Implications for Evolution via Gene Duplication and Divergence |
| title_full | Mutational Pathways and Trade-Offs Between HisA and TrpF Functions: Implications for Evolution via Gene Duplication and Divergence |
| title_fullStr | Mutational Pathways and Trade-Offs Between HisA and TrpF Functions: Implications for Evolution via Gene Duplication and Divergence |
| title_full_unstemmed | Mutational Pathways and Trade-Offs Between HisA and TrpF Functions: Implications for Evolution via Gene Duplication and Divergence |
| title_short | Mutational Pathways and Trade-Offs Between HisA and TrpF Functions: Implications for Evolution via Gene Duplication and Divergence |
| title_sort | mutational pathways and trade offs between hisa and trpf functions implications for evolution via gene duplication and divergence |
| topic | duplication divergence trade-off HISA TrpF Salmonella enterica |
| url | https://www.frontiersin.org/article/10.3389/fmicb.2020.588235/full |
| work_keys_str_mv | AT eriklundin mutationalpathwaysandtradeoffsbetweenhisaandtrpffunctionsimplicationsforevolutionviageneduplicationanddivergence AT joakimnasvall mutationalpathwaysandtradeoffsbetweenhisaandtrpffunctionsimplicationsforevolutionviageneduplicationanddivergence AT daniandersson mutationalpathwaysandtradeoffsbetweenhisaandtrpffunctionsimplicationsforevolutionviageneduplicationanddivergence |