Cargando…

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...

Descripción completa

Detalles Bibliográficos
Autores principales: Morse, Michael, Naufer, M Nabuan, Feng, Yuqing, Chelico, Linda, Rouzina, Ioulia, Williams, Mark C
Formato: Online Artículo Texto
Lenguaje:English
Publicado: eLife Sciences Publications, Ltd 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6946564/
https://www.ncbi.nlm.nih.gov/pubmed/31850845
http://dx.doi.org/10.7554/eLife.52649
_version_ 1783485388619251712
author Morse, Michael
Naufer, M Nabuan
Feng, Yuqing
Chelico, Linda
Rouzina, Ioulia
Williams, Mark C
author_facet Morse, Michael
Naufer, M Nabuan
Feng, Yuqing
Chelico, Linda
Rouzina, Ioulia
Williams, Mark C
author_sort Morse, Michael
collection PubMed
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.
format Online
Article
Text
id pubmed-6946564
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher eLife Sciences Publications, Ltd
record_format MEDLINE/PubMed
spelling pubmed-69465642020-01-09 HIV restriction factor APOBEC3G binds in multiple steps and conformations to search and deaminate single-stranded DNA Morse, Michael Naufer, M Nabuan Feng, Yuqing Chelico, Linda Rouzina, Ioulia Williams, Mark C eLife Structural Biology and Molecular Biophysics 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. eLife Sciences Publications, Ltd 2019-12-18 /pmc/articles/PMC6946564/ /pubmed/31850845 http://dx.doi.org/10.7554/eLife.52649 Text en © 2019, Morse et al http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use and redistribution provided that the original author and source are credited.
spellingShingle Structural Biology and Molecular Biophysics
Morse, Michael
Naufer, M Nabuan
Feng, Yuqing
Chelico, Linda
Rouzina, Ioulia
Williams, Mark C
HIV restriction factor APOBEC3G binds in multiple steps and conformations to search and deaminate single-stranded DNA
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 Structural Biology and Molecular Biophysics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6946564/
https://www.ncbi.nlm.nih.gov/pubmed/31850845
http://dx.doi.org/10.7554/eLife.52649
work_keys_str_mv AT morsemichael hivrestrictionfactorapobec3gbindsinmultiplestepsandconformationstosearchanddeaminatesinglestrandeddna
AT naufermnabuan hivrestrictionfactorapobec3gbindsinmultiplestepsandconformationstosearchanddeaminatesinglestrandeddna
AT fengyuqing hivrestrictionfactorapobec3gbindsinmultiplestepsandconformationstosearchanddeaminatesinglestrandeddna
AT chelicolinda hivrestrictionfactorapobec3gbindsinmultiplestepsandconformationstosearchanddeaminatesinglestrandeddna
AT rouzinaioulia hivrestrictionfactorapobec3gbindsinmultiplestepsandconformationstosearchanddeaminatesinglestrandeddna
AT williamsmarkc hivrestrictionfactorapobec3gbindsinmultiplestepsandconformationstosearchanddeaminatesinglestrandeddna