{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,7,2]],"date-time":"2025-07-02T18:11:48Z","timestamp":1751479908406},"reference-count":54,"publisher":"American Society for Microbiology","issue":"3","license":[{"start":{"date-parts":[[2004,3,1]],"date-time":"2004-03-01T00:00:00Z","timestamp":1078099200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["Infect Immun"],"published-print":{"date-parts":[[2004,3]]},"abstract":"<jats:title>ABSTRACT<\/jats:title><jats:p>The gonococcal transferrin receptor is composed of two distinct proteins, TbpA and TbpB. TbpA is a member of the TonB-dependent family of integral outer membrane transporters, while TbpB is lipid modified and thought to be peripherally surface exposed. We previously proposed a hypothetical topology model for gonococcal TbpA that was based upon computer predictions and similarity with other TonB-dependent transporters for which crystal structures have been determined. In the present study, the hemagglutinin epitope was inserted into TbpA to probe the surface topology of this protein and secondarily to test the functional impacts of site-specific mutagenesis. Twelve epitope insertion mutants were constructed, five of which allowed us to confirm the surface exposure of loops 2, 3, 5, 7, and 10. In contrast to the predictions set forth by the hypothetical model, insertion into the plug region resulted in an epitope that was surface accessible, while epitope insertions into two putative loops (9 and 11) were not surface accessible. Insertions into putative loop 3 and \u03b2 strand 9 abolished transferrin binding and utilization, and the plug insertion mutant exhibited decreased transferrin-binding affinity concomitant with an inability to utilize it. Insertion into putative \u03b2 strand 16 generated a mutant that was able to bind transferrin normally but that was unable to mediate utilization. Mutants with insertions into putative loops 2, 9, and 11 maintained wild-type binding affinity but could utilize only transferrin in the presence of TbpB. This is the first demonstration of the ability of TbpB to compensate for a mutation in TbpA.<\/jats:p>","DOI":"10.1128\/iai.72.3.1775-1785.2004","type":"journal-article","created":{"date-parts":[[2004,2,21]],"date-time":"2004-02-21T04:42:58Z","timestamp":1077338578000},"page":"1775-1785","update-policy":"http:\/\/dx.doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":22,"title":["Determination of Surface-Exposed, Functional Domains of Gonococcal Transferrin-Binding Protein A"],"prefix":"10.1128","volume":"72","author":[{"given":"Mary Kate","family":"Yost-Daljev","sequence":"first","affiliation":[{"name":"Department of Microbiology and Immunology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia 23298-0678"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cynthia Nau","family":"Cornelissen","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia 23298-0678"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"235","reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.177.16.4742-4747.1995"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.176.11.3162-3170.1994"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.270.6.2483"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.67.1.455-459.1999"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.68.12.6988-6996.2000"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.175.10.3146-3150.1993"},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.1016\/0014-5793(94)00431-5"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1038\/4931"},{"key":"e_1_3_2_10_2","first-page":"1","volume":"80","year":"1978","unstructured":"Bullen, J. J., H. J. Rogers, and E. Griffiths. 1978. Role of iron in bacterial infection. Curr. Top. Microbiol. Immunol.80:1-35.","journal-title":"Curr. Top. Microbiol. Immunol."},{"key":"e_1_3_2_11_2","first-page":"547","volume":"134","year":"1988","unstructured":"Burnstein, K. L., D. W. Dyer, and P. F. Sparling. 1988. Preferential uptake of restriction fragments from a gonococcal cryptic plasmid by competent Neisseria gonorrhoeae.J. Gen. Microbiol.134:547-557.","journal-title":"J. Gen. Microbiol."},{"key":"e_1_3_2_12_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.96.19.10673"},{"key":"e_1_3_2_13_2","doi-asserted-by":"publisher","DOI":"10.1002\/j.1460-2075.1986.tb04602.x"},{"key":"e_1_3_2_14_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.173.1.262-275.1991"},{"key":"e_1_3_2_15_2","doi-asserted-by":"publisher","DOI":"10.2741\/1076"},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.68.8.4725-4735.2000"},{"key":"e_1_3_2_17_2","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2958.1997.5381914.x"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.175.8.2448-2450.1993"},{"key":"e_1_3_2_19_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.174.18.5788-5797.1992"},{"key":"e_1_3_2_20_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.178.5.1437-1444.1996"},{"key":"e_1_3_2_21_2","doi-asserted-by":"publisher","DOI":"10.1016\/0264-410X(93)90045-Y"},{"key":"e_1_3_2_22_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0005-2736(02)00578-3"},{"key":"e_1_3_2_23_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.282.5397.2215"},{"key":"e_1_3_2_24_2","doi-asserted-by":"publisher","DOI":"10.1016\/0264-410X(95)00055-6"},{"key":"e_1_3_2_25_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.152.3.1071-1077.1982"},{"key":"e_1_3_2_26_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.171.12.6526-6533.1989"},{"key":"e_1_3_2_27_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF02173639"},{"key":"e_1_3_2_28_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.180.22.6031-6038.1998"},{"key":"e_1_3_2_29_2","first-page":"528","volume":"8","year":"1990","unstructured":"Horton, R. M., Z. L. Cai, S. N. Ho, and L. R. Pease. 1990. Gene splicing by overlap extension: tailor-made genes using the polymerase chain reaction. BioTechniques8:528-535.","journal-title":"BioTechniques"},{"key":"e_1_3_2_30_2","doi-asserted-by":"publisher","DOI":"10.1007\/s002849900339"},{"key":"e_1_3_2_31_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2958.1990.tb00562.x"},{"key":"e_1_3_2_32_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.85.6.1274-1279.1963"},{"key":"e_1_3_2_33_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.184.22.6138-6145.2002"},{"key":"e_1_3_2_34_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.178.23.6913-6920.1996"},{"key":"e_1_3_2_35_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.175.3.826-839.1993"},{"key":"e_1_3_2_36_2","doi-asserted-by":"publisher","DOI":"10.1038\/227680a0"},{"key":"e_1_3_2_37_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.179.10.3213-3221.1997"},{"key":"e_1_3_2_38_2","doi-asserted-by":"publisher","DOI":"10.1016\/0264-410X(89)90237-5"},{"key":"e_1_3_2_39_2","doi-asserted-by":"publisher","DOI":"10.1128\/iai.63.3.884-890.1995"},{"key":"e_1_3_2_40_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.90.22.10653"},{"key":"e_1_3_2_41_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(18)67457-5"},{"key":"e_1_3_2_42_2","unstructured":"Maniatis T. E. F. Fritsch and J. Sambrook. 1982. Molecular cloning: a laboratory manual. Cold Spring Harbor Laboratory Press Cold Spring Harbor N.Y."},{"key":"e_1_3_2_43_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.70.2.732-740.2002"},{"key":"e_1_3_2_44_2","doi-asserted-by":"publisher","DOI":"10.1128\/iai.33.2.555-564.1981"},{"key":"e_1_3_2_45_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.176.14.4250-4259.1994"},{"key":"e_1_3_2_46_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.177.21.6118-6125.1995"},{"key":"e_1_3_2_47_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.178.12.3447-3456.1996"},{"key":"e_1_3_2_48_2","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2958.1999.01424.x"},{"key":"e_1_3_2_49_2","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1007\/BF00770246","volume":"25","year":"1993","unstructured":"Postle, K. 1993. TonB protein and energy transduction between membranes. J. Bioenerg. Biomembr.25:591-601.","journal-title":"J. Bioenerg. Biomembr."},{"key":"e_1_3_2_50_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF02464907"},{"key":"e_1_3_2_51_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.172.1.40-46.1990"},{"key":"e_1_3_2_52_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.181353398"},{"key":"e_1_3_2_53_2","doi-asserted-by":"publisher","DOI":"10.1353\/pbm.1997.0072"},{"key":"e_1_3_2_54_2","doi-asserted-by":"publisher","DOI":"10.1128\/iai.47.2.388-394.1985"},{"key":"e_1_3_2_55_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.169.8.3414-3421.1987"}],"container-title":["Infection and Immunity"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/IAI.72.3.1775-1785.2004","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/IAI.72.3.1775-1785.2004","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,4,28]],"date-time":"2023-04-28T00:26:21Z","timestamp":1682641581000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/IAI.72.3.1775-1785.2004"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2004,3]]},"references-count":54,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2004,3]]}},"alternative-id":["10.1128\/IAI.72.3.1775-1785.2004"],"URL":"https:\/\/doi.org\/10.1128\/iai.72.3.1775-1785.2004","relation":{},"ISSN":["0019-9567","1098-5522"],"issn-type":[{"value":"0019-9567","type":"print"},{"value":"1098-5522","type":"electronic"}],"subject":[],"published":{"date-parts":[[2004,3]]},"assertion":[{"value":"2003-10-15","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2003-12-19","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2004-03-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}