{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T16:43:17Z","timestamp":1781109797935,"version":"3.54.1"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"4","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1974,4]]},"abstract":"<jats:p>\n                    Tyrosyl or other aromatic residues generally occur in two conserved positions in the peptide chain of clostridial-type ferredoxins and have been implicated in the electron transfer function of these iron-sulfur proteins. We have prepared and determined some of the properties of a derivative of\n                    <jats:italic>Clostridium acidi-urici<\/jats:italic>\n                    ferredoxin, [Leu\n                    <jats:sup>2<\/jats:sup>\n                    ]-ferredoxin, in which a leucyl residue has been substituted for the tyrosyl residue in position 2 from the amino terminus. [Leu\n                    <jats:sup>2<\/jats:sup>\n                    ]-ferredoxin is fully active as an electron carrier in two biological assays, the phosphoroclastic enzyme system and the ferredoxin-dependent reduction of cytochrome\n                    <jats:italic>c<\/jats:italic>\n                    in the presence of ferredoxin-TPN reductase and TPNH. Quantitative electron paramagnetic resonance experiments indicate that [Leu\n                    <jats:sup>2<\/jats:sup>\n                    ]-ferredoxin accepts nearly two electrons upon enzymatic reduction by pyruvate-ferredoxin oxidoreductase and an excess of pyruvate. If electron transfer to an iron-sulfur cluster is the rate-limiting step in the assays used, and if the rate of electron transfer through Tyr\n                    <jats:sup>30<\/jats:sup>\n                    is not much faster than through Tyr\n                    <jats:sup>2<\/jats:sup>\n                    , these results indicate that the primary pathway of electron transfer in clostridial-type ferredoxins is not via Tyr or other aromatic amino-acid residues. The syntheses of other ferredoxin derivatives with amino-acid substitutions or deletions in positions 1 and 2 indicate that a large bulky residue, but not necessarily an aromatic residue, is needed in position 2 for the stability of this ferredoxin. The residue in position 2, therefore, appears to act as a hydrophobic shield for an iron-sulfur cluster.\n                  <\/jats:p>","DOI":"10.1073\/pnas.71.4.1361","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T02:53:50Z","timestamp":1149044030000},"page":"1361-1365","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":26,"title":["Synthesis and Properties of\n                    <i>Clostridium acidi-urici<\/i>\n                    [Leu\n                    <sup>2<\/sup>\n                    ]-Ferredoxin: A Function of the Peptide Chain and Evidence Against the Direct Role of the Aromatic Residues in Electron Transfer"],"prefix":"10.1073","volume":"71","author":[{"given":"Eglis T.","family":"Lode","sequence":"first","affiliation":[{"name":"Department of Biochemistry, University of California, Berkeley, Calif. 94720"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cheryl L.","family":"Murray","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, University of California, Berkeley, Calif. 94720"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"William V.","family":"Sweeney","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, University of California, Berkeley, Calif. 94720"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jesse C.","family":"Rabinowitz","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, University of California, Berkeley, Calif. 94720"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1974,4]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.71.4.1361","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T10:45:26Z","timestamp":1649846726000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.71.4.1361"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1974,4]]},"references-count":0,"journal-issue":{"issue":"4","published-print":{"date-parts":[[1974,4]]}},"alternative-id":["10.1073\/pnas.71.4.1361"],"URL":"https:\/\/doi.org\/10.1073\/pnas.71.4.1361","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1974,4]]},"assertion":[{"value":"1974-04-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}