[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-657138-105":59,"doc-detail-657138-en":124},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":117,"head_meta":119,"extra_data":121,"updated_unix":123},105,"en","molecular-structure-of-nucleic-acids-a-structure-for-deoxyribose-nucleic-acid","MOLECULAR STRUCTURE OF NUCLEIC ACIDS - A Structure for Deoxyribose Nucleic Acid","","A proposed salt structure for deoxyribose nucleic acid is presented as a radically different double-helix arrangement with two helical chains sharing the same axis. The chains run in opposite atomic directions and feature phosphate diester groups and ß-D-deoxy ribofuranose residues linked by 3’,5’ linkages. Base planes are perpendicular to the fibre axis and pair via specific hydrogen bonding: adenine-thymine and guanine-cytosine. The model implies an open, water-rich structure and suggests a mechanism for genetic copying, while noting that existing X-ray data are not sufficient for full validation.",{"@graph":69,"@context":116},[70,84,99],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":40,"@type":76,"position":81},"https://docshare.wps.com/document/research-report/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/molecular-structure-of-nucleic-acids-a-structure-for-deoxyribose-nucleic-acid/657138/",{"url":83,"name":65,"@type":85,"author":86,"headline":65,"publisher":89,"fileFormat":92,"inLanguage":63,"description":67,"dateModified":93,"datePublished":93,"encodingFormat":92,"isAccessibleForFree":94,"interactionStatistic":95},"DigitalDocument",{"name":87,"@type":88},"Dewi_Sukmawati","Person",{"url":74,"name":90,"@type":91},"DocShare","Organization","application/pdf","2026-10-26",true,{"@type":96,"interactionType":97,"userInteractionCount":4},"InteractionCounter",{"@type":98},"ViewAction",{"@type":100,"mainEntity":101},"FAQPage",[102,108,112],{"name":103,"@type":104,"acceptedAnswer":105},"Why do the authors consider earlier three-chain models unsatisfactory?","Question",{"text":106,"@type":107},"They argue the X-ray material corresponds to the salt rather than the free acid, and without acidic hydrogen atoms the forces holding the structure together are unclear. They also find some van der Waals distances in the earlier models appear too small.","Answer",{"name":109,"@type":104,"acceptedAnswer":110},"What is the key structural feature of the proposed deoxyribose nucleic acid model?",{"text":111,"@type":107},"The model uses two helical chains coiled around the same axis, held together specifically by hydrogen bonding between complementary purine and pyrimidine bases.",{"name":113,"@type":104,"acceptedAnswer":114},"Which base pairs does the structure require for bonding to occur?",{"text":115,"@type":107},"Only adenine with thymine, and guanine with cytosine, in specific hydrogen-bonding positions are compatible with the assumed tautomeric forms.","https://schema.org",{"og:url":83,"og:type":118,"og:title":65,"og:site_name":90,"og:description":67},"article",{"robots":120,"canonical":83},"index,follow",{"doc_id":122,"site_id":62},657138,1792974751,{"code":4,"msg":5,"data":125},{"doc_id":122,"user_id":126,"nickname":87,"user_avatar":127,"doc_module":4,"category_id":39,"category_name":40,"doc_title":65,"doc_description":67,"doc_content":128,"file_id":129,"file_url":130,"file_type":131,"file_size":132,"view_count":4,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":8,"language":133,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":134,"faqs":135,"seo_title":136,"seo_description":67,"update_tm":123,"read_time":81},962094243415,"https://ap-avatar.wpscdn.com/davatar_3d24733baf745e90a7e4bdd5f77d97b2","No. 4356 April 25, 1953 NATURE  \n737  \nMOLECULAR STRUCTURE OF NUCLEIC ACIDS  \nA Structure for Deoxyribose Nucleic Acid  \nE wish to suggest a structure for the salt of deoxyribose Wnuclewhichicaraedf cs.Nid.Aera.)b. lTehisbiolsotgucturecal inteasst . novel features A structure for nucleic acid has already been proposed by Pauling and Corey1. They kindly made their manuscript available to us in advance of publication. Their model consists of three intertwined chains, with the phosphates near the fibre axis, and the bases on the outside. In our opinion. this structure is unsatisfactory for two reasons:  \n(1) We believe that the material which gives the X-ray diagrams is the salt, not the free acid. Without the acidic hydrogen atoms it isnot clear what forces would hold the structure together, especially as the negatively charged phosphates near the axis will repel eachother. (2) Some of the van der Waals distances appear to be too small.  \nAnother three-chain structure has also been suggested by Fraser (in the press) . In his model the phosphates are on the outside and the bases on the inside, linked together by hydrogen bonds. This structure as described is rather ill-defined, and for this reason we shall not comment on it.  \nWe wish to put forward a radically different structure for the salt of deoxyribose nucleic acid. This structure has two helical chains each coiled round the same axis (see diagram) . We have made the usual chemical assumptions. namely, that each chain consists of phosphate diester groups joining ß-D-deoxy ribofuranose residues with 3’,5’ linkages. The two chains (but not their bases) are related by a dyad perpendicular to the fibre axis. Both chains follow righthanded helices, but owing to the dyad the sequences ofthe atoms in the two chains run in opposite directions. Each chain loosely resembles Furberg’s2 model No. 1; that is, the bases are on the inside of the helix and the phosphates on the outside. The configuration of the sugar and the atoms near it is close to Furberg’s standard configuration’, the sugar being roughly perpendicular to the attached base. There is a residue on each chain every [3-4 A. in](3-4 A. in) the z-direction. We have assumed an angle of 36° between adjacent residues in the same chain, so that the structure repeats after 10 residues on each chain, that is, after 34 A. The distance of a phosphorus atom from the fibre axis is 10 A. As the phosphates are on the outside, cations have easy access to them.  \nThe structure is an open one, and its water content is rather high. At lower water contents we would expect the bases to tilt so that the structure could become more compact.  \nThe novel feature of the structure is the manner in which the two chains are held together by the purine and pyrimidine bases. The planes of the bases are perpendicular to the fibre axis. They are joined together in pairs, a single base from one chain being hydrogen-bonded to a single base from the other chain, so  \nThis figure is purely diagrammatic. The two ribbons synibolize the two orispzoate—sutal rodsgtahre cpainsso,fanbstee holding the cbains together. The vertical line marks the fibre axis  \nthat the two lie side by side with identical z-co-ordinates. One of the pair must be a purine and the other a pyrimidine for bonding to occur. The hydrogen bonds are made as follows: purine position 1 to pyrimidine position 1; purine position 6 to pyrimidine position 6.  \nIf it is assumed that the bases only occur in the structure in the most plausible tautomeric forms (that is, with the keto rather than the enol configurations) it is found that only specific pairs of bases can bond together. These pairs are: adenine (purine) with thymine (pyrimidine), and guanine (purine) with cytosine (pyrimidine) .  \nIn other words, if an adenine forms one member of a pair, on either chain, then on these assumptions the other member must be thymine; similarly for guanine and cytosine. The sequence of bases on a single chain, ","cbCaib2kH5EJcp5A","https://ap.wps.com/l/cbCaib2kH5EJcp5A","pdf",41473,"English","# Molecular structure of nucleic acids\n## Proposed structure for deoxyribose nucleic acid\n## Base pairing rules and implications","[{\"question\":\"Why do the authors consider earlier three-chain models unsatisfactory?\",\"answer\":\"They argue the X-ray material corresponds to the salt rather than the free acid, and without acidic hydrogen atoms the forces holding the structure together are unclear. They also find some van der Waals distances in the earlier models appear too small.\"},{\"question\":\"What is the key structural feature of the proposed deoxyribose nucleic acid model?\",\"answer\":\"The model uses two helical chains coiled around the same axis, held together specifically by hydrogen bonding between complementary purine and pyrimidine bases.\"},{\"question\":\"Which base pairs does the structure require for bonding to occur?\",\"answer\":\"Only adenine with thymine, and guanine with cytosine, in specific hydrogen-bonding positions are compatible with the assumed tautomeric forms.\"}]","MOLECULAR STRUCTURE OF NUCLEIC ACIDS - A Structure for Deoxyribose Nucleic Acid | PDF"]