JOURNAL OF BACTERIOLOGY VOLUME 174 * DECEMBER 1992 * NUMBER 24 Graham C. Walker, Editor in Chief (1996) Dale Kaiser, Minireview Editor (1994) Massachusetts Institute of Technology, Stanford University School of Cambridge, Mass. Susan Gottesman, Editor (1994) Medicine, Stanford, Calif. National Cancer Institute, Editor (1997) Bethesda, Md. A. L. Sonenshein, Editor (1995) Terrance J. Beveridge, Boston, Mass. University of Guelph, Guelph, Canada E. Peter Greenberg, Editor (1996) Tufts University, University ofIowa, Iowa Kenneth N. Timmis, Editor (1997) James G. Ferry, Editor (1996) City, Iowa Virginia Polytechnic Institute and GBF, Braunschweig, Gennany State University, Blacksburg, Va. Carol A. Gross, Editor (1995) Robert A. Weisberg, Editor (1995) University of Wisconsin, National Institute of Child Dan Fraenkel, Editor (1996) Madison, Wis. Health and Human Harvard Medical School, Boston, Mass. Development, Bethesda, Md. EDITORIAL BOARD Sankar Adhya (1993) Susan H. Fisher (1994) Thomas Lessie (1992) H. Steven Seifert (1994) Stuart J. Austin (1993) Patricia L. Foster (1993) Roger C. Levesque (1994) Peter Setlow (1993) Barbara Bachmann (1993) Michael G. Fried (1994) Mary E. Lidstrom (1993) Hideo Shinagawa (1994) Margaret H. Bayer (1992) David I. Friedman (1992) E. C. C. Lin (1994) Howard A. Shuman (1994) Douglas E. Berg (1994) Barbel Friedrich (1993) Lasse Lindahl (1993) Gerald Smith (1994) Robert W. Bernlohr (1994) Clement Furlong (1993) John W. Little (1992) Issar Smith (1993) Volkmar Braun (1992) Robert Gennis (1994) Jack London (1993) G. Dennis Sprott (1992) Richard Calendar (1994) Costa P. Georgopoulos (1993) Sharon Long (1992) Catherine Squires (1993) George M. Carman (1994) Jane Gibson (1994) Paul S. Lovett (1993) Gary Stacey (1994) Sherwood Casjens (1994) Larry Gold (1994) Paul W. Ludden (1993) David Stahl (1993) A. M. Chakrabarty (1992) Susan Golden (1994) Ben Lugtenberg (1992) Brian Staskawicz (1993) Trinad Chakraborty (1994) Richard L. Gourse (1994) Robert Macnab (1994) Robert Steffan (1993) Wendy C. Champness (1994) Nigel Grindley (1993) Martin Marinus (1992) Michel Steinmetz (1994) Mick Chandler (1993) Alan Grossman (1994) Millicent Masters (1992) Valley Stewart (1994) Keith F. Chater (1994) Robert P. Gunsalus (1993) Abdul Matin (1993) Susan C. Straley (1994) Terrence G. Cooper (1993) William Haldenwang (1994) Philip Matsumura (1992) F. William Studier (1992) David L. Coplin (1992) Richard S. Hanson (1994) Russell Maurer (1993) Anne 0. Summers (1993) Donald Court (1994) Shigeaki Harayama (1993) John Mekalanos (1994) Robert Switzer (1993) R. L. Crawford (1993) Robert Haselkorn (1993) Paul Messner (1993) Andrew Taylor (1994) John E. Cronan, Jr. (1992) Gerald L. Hazelbauer (1993) Charles G. Miller (1994) Nancy Trun (1994) Jorge H. Crosa (1994) George D. Hegeman (1994) Virginia Miller (1994) Trevor R. Trust (1994) Stanley J. Cryz, Jr. (1994) Roger Hendrix (1992) Shoji Mizushima (1994) Charles L. Turnbough, Jr. Lacy Daniels (1992) C. F. Higgins (1993) Charles P. Moran, Jr. (1994) (1993) Richard D'Ari (1994) Joachim-Volker Holtje (1993) Edward A. Morgan (1993) Ronald Unterman (1994) Victor de Lorenzo (1994) Karin Ippen-Ihler (1993) Gisela Mosig (1994) Mark Walker (1993) Bruce Demple (1994) Edward E. Ishiguro (1994) Francis E. Nano (1994) Judy D. Wall (1993) Patrick P. Dennis (1993) Gerald Johnston (1993) Dale Noel (1994) Barry Wanner (1993) Migel A. de Pedro (1993) Robert J. Kadner (1992) Staffan Normark (1994) Chris M. Whitfield (1992) William D. Donachie (1994) Clarence I. Kado (1994) Dennis Ohman (1994) William B. Whitman (1994) Timothy Donohue (1993) Noel Keen (1994) Gary Olsen (1994) Peter A. Williams (1992) Ron J. Doyle (1994) Eduard J. Kellenberger (1992) John S. Parkinson (1993) Stephen C. Winans (1994) David A. Dubnau (1992) Patricia Kiley (1994) Thomas R. Parr (1994) Malcolm Winkler (1994) Daniel Dykhuizen (1994) H.-J. Knackmuss (1993) Anthony Pugsley (1994) C. L. Woldringh (1993) S. Dusko Ehrlich (1994) Roberto Kolter (1994) Juan L. Ramos (1993) Hans Wolf-Watz (1994) Rudolf Eichenlaub (1994) Wil N. Konings (1993) Linda Randall (1993) David Womble (1992) Lindsay D. Eltis (1994) Dennis J. Kopecko (1993) Gary P. Roberts (1993) John L. Woolford (1994) Bert Ely (1994) Susan F. Koval (1994) Jeffrey Roberts (1992) Henry C. Wu (1993) Wolfgang Epstein (1993) Terry Ann Krulwich (1993) Charles 0. Rock (1993) Ryland Young (1993) Jeff Errington (1994) Carol Kumamoto (1993) Lucia B. Rothman-Denes (1992) Takashi Yura (1994) Jorge Escalante-Semerena (1994) Harald Labischinski (1992) Kenneth E. Rudd (1994) Howard Zalkin (1994) David H. Figurski (1993) Joseph Lam (1994) Rudiger Schmitt (1992) Barbara H. Iglewski, Chairman, Publications Board Linda M. Illig, Director, Journals Sara C. Joslyn, Production Editor Catherine E. 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Author Index Abedon, Stephen T., 8073 Giordano, Gerard, 7934 Liautard, J. P., 8036 Rothstein, David M., 7926 Asada, Kiyozo, 8163 Goebel, Werner, 8166 Lobner-Olesen, Anders, 7883 Gruber, Karin, 8008 Luck, B. T., 8139 Sadouk, A., 8133 Ball, Catherine A., 8043 Gupta, Dhirendra S., 7963 Sahm, Hermann, 8065 Banerjee, S. K., 8139 Magill, Nancy G., 8148 Sandman, Kathleen M., 7890 Beale, Samuel I., 7910 Hall, Belinda M., 8156 Marti, J., 8036 Santini, Claire-Lise, 7934 Beveridge, Terry J., 7971 Hansson, Mats, 8081 McKenney, Keith, 8030 Schultze-Lam, Susanne, 7971 Borremans, B., 8133 Harasawa, Ry6, 8163 McNicholas, Paul, 7926 Setlow, Peter, 8148 Boxer, David H., 7934 Harauz, George, 7971 Meganathan, R., 8111 Shakibai, Nader, 7982 Brakier-Gingras, Lea, 7896 Hartline, Kelly M., 8156 Melan,on, Pierre, 7896 Sharma, V., 8111 Breitwieser, Andreas, 8008 Hederstedt, Lars, 8081 Mergeay, M., 8133 Shashkov, Alexander S., 7963 Bubert, Andreas, 8166 Helinski, Donald R., 8119 Mockel, Bettina, 8065 Sleytr, Uwe B., 8008 Helmstetter, Charles E., 8152 Moore, Julie, 8030 Stevens, Barry J. H., 7941 Canale-Parola, Ercole, 7996 Hsing, Weihong, 7996 Morris, Victor J., 7941 Summers, Anne O., 8094 Cellier, M. F. M., 8036 Hudspeth, M. E. S., 8111 Muda, M., 8057 Tabassum, Romana, 7890 Chen, Jychien, 8023 Mukai, Kuniaki, 7954 Ike, Yasuyoshi, 8172 Taghavi, S., 8133 Chopra, Ian, 7926 Mukohara, Yukuo, 7989 Tanaka, Teruo, 7954 Chow, Wei-Yuan, 8023 Iobbi-Nivol, Chantal, 7934 Ishidate, Kohei, 7982 Tapprich, William E., 7896 Clewell, Don B., 8172 Nakagawa, Tomoko, 8163 Teyssier, J., 8036 Collins, Matthew D., 8158 Ishikawa, Takahiro, 7989 Nakamura, Hiroaki, 7989 Iyer, V. N., 8139 Thompson, Daphne E., 8158 Condee, Charles W., 8094 Negoro, Seiji, 7948 Topp, Edward, 8003 Jann, Barbara, 7963 Nicolas, M., 8036 Torriani, A., 8057 Damani, Karima, 7941 Jann, Klaus, 7963 Nies, Dietrich H., 8102 Toussaint, A., 8133 Debouck, Christine, 7902 Johnson, Reid C., 8043 Nuyten, J. M., 8133