HIV restriction factor APOBEC3G binds in multiple steps and conformations to search and deaminate single-stranded DNA
APOBEC3G (A3G), an enzyme expressed in primates with the potential to inhibit human immunodeficiency virus type 1 (HIV-1) infectivity, is a single-stranded DNA (ssDNA) deoxycytidine deaminase with two domains, a catalytically active, weakly ssDNA binding C-terminal domain (CTD) and a catalytically in...
| Main Authors: | , , , , , |
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| Format: | Article |
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eLife Sciences Publications Ltd
2019-12-01
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| Series: | eLife |
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| Online Access: | https://elifesciences.org/articles/52649 |
| _version_ | 1828376314582663168 |
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| author | Michael Morse M Nabuan Naufer Yuqing Feng Linda Chelico Ioulia Rouzina Mark C Williams |
| author_facet | Michael Morse M Nabuan Naufer Yuqing Feng Linda Chelico Ioulia Rouzina Mark C Williams |
| author_sort | Michael Morse |
| collection | DOAJ |
| description | APOBEC3G (A3G), an enzyme expressed in primates with the potential to inhibit human immunodeficiency virus type 1 (HIV-1) infectivity, is a single-stranded DNA (ssDNA) deoxycytidine deaminase with two domains, a catalytically active, weakly ssDNA binding C-terminal domain (CTD) and a catalytically inactive, strongly ssDNA binding N-terminal domain (NTD). Using optical tweezers, we measure A3G binding a single, long ssDNA substrate under various applied forces to characterize the binding interaction. A3G binds ssDNA in multiple steps and in two distinct conformations, distinguished by degree of ssDNA contraction. A3G stabilizes formation of ssDNA loops, an ability inhibited by A3G oligomerization. Our data suggests A3G securely binds ssDNA through the NTD, while the CTD samples and potentially deaminates the substrate. Oligomerization of A3G stabilizes ssDNA binding but inhibits the CTD’s search function. These processes explain A3G’s ability to efficiently deaminate numerous sites across a 10,000 base viral genome during the reverse transcription process. |
| first_indexed | 2024-04-14T07:58:16Z |
| format | Article |
| id | doaj.art-4c1563b21f9c43f0bb7ba7c8cd958b86 |
| institution | Directory Open Access Journal |
| issn | 2050-084X |
| language | English |
| last_indexed | 2024-04-14T07:58:16Z |
| publishDate | 2019-12-01 |
| publisher | eLife Sciences Publications Ltd |
| record_format | Article |
| series | eLife |
| spelling | doaj.art-4c1563b21f9c43f0bb7ba7c8cd958b862022-12-22T02:04:58ZengeLife Sciences Publications LtdeLife2050-084X2019-12-01810.7554/eLife.52649HIV restriction factor APOBEC3G binds in multiple steps and conformations to search and deaminate single-stranded DNAMichael Morse0https://orcid.org/0000-0002-8561-1833M Nabuan Naufer1Yuqing Feng2Linda Chelico3Ioulia Rouzina4Mark C Williams5https://orcid.org/0000-0003-3219-376XDepartment of Physics, Northeastern University, Boston, United StatesDepartment of Physics, Northeastern University, Boston, United StatesDepartment of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, CanadaDepartment of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, CanadaDepartment of Chemistry and Biochemistry, Ohio State University, Columbus, United StatesDepartment of Physics, Northeastern University, Boston, United StatesAPOBEC3G (A3G), an enzyme expressed in primates with the potential to inhibit human immunodeficiency virus type 1 (HIV-1) infectivity, is a single-stranded DNA (ssDNA) deoxycytidine deaminase with two domains, a catalytically active, weakly ssDNA binding C-terminal domain (CTD) and a catalytically inactive, strongly ssDNA binding N-terminal domain (NTD). Using optical tweezers, we measure A3G binding a single, long ssDNA substrate under various applied forces to characterize the binding interaction. A3G binds ssDNA in multiple steps and in two distinct conformations, distinguished by degree of ssDNA contraction. A3G stabilizes formation of ssDNA loops, an ability inhibited by A3G oligomerization. Our data suggests A3G securely binds ssDNA through the NTD, while the CTD samples and potentially deaminates the substrate. Oligomerization of A3G stabilizes ssDNA binding but inhibits the CTD’s search function. These processes explain A3G’s ability to efficiently deaminate numerous sites across a 10,000 base viral genome during the reverse transcription process.https://elifesciences.org/articles/52649force spectroscopyprotein-DNA bindingoligomerizationfacilitated diffusionHIV-1 restriction |
| spellingShingle | Michael Morse M Nabuan Naufer Yuqing Feng Linda Chelico Ioulia Rouzina Mark C Williams HIV restriction factor APOBEC3G binds in multiple steps and conformations to search and deaminate single-stranded DNA eLife force spectroscopy protein-DNA binding oligomerization facilitated diffusion HIV-1 restriction |
| title | HIV restriction factor APOBEC3G binds in multiple steps and conformations to search and deaminate single-stranded DNA |
| title_full | HIV restriction factor APOBEC3G binds in multiple steps and conformations to search and deaminate single-stranded DNA |
| title_fullStr | HIV restriction factor APOBEC3G binds in multiple steps and conformations to search and deaminate single-stranded DNA |
| title_full_unstemmed | HIV restriction factor APOBEC3G binds in multiple steps and conformations to search and deaminate single-stranded DNA |
| title_short | HIV restriction factor APOBEC3G binds in multiple steps and conformations to search and deaminate single-stranded DNA |
| title_sort | hiv restriction factor apobec3g binds in multiple steps and conformations to search and deaminate single stranded dna |
| topic | force spectroscopy protein-DNA binding oligomerization facilitated diffusion HIV-1 restriction |
| url | https://elifesciences.org/articles/52649 |
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