271:). Thus, the more RepA is made, the more its synthesis is repressed, and subsequently limiting plasmid replication. The coupling hypothesis proposes that the second method is coupling of plasmids through the Rep protein and iteron sequences. When the plasmid concentration is high, RepA plasmids bound to iterons form dimers in between two plasmids, "handcuffing" them at the origin of replication and inhibiting replication.
170:(repressor of primer) and a double-stranded RNA-I/RNA-II RNA duplex is formed. This altered shape prevents RNA II from hybridizing to the DNA and being processed from RNaseH to produce the primer necessary for initiation of plasmid replication. More RNA I is produced as the plasmid concentration increases, which increasingly inhibits replication, resulting in regulation of copy number.
22:
108:(>100 copies/cell) have been derived by mutagenesis, such as the well known pUC series. This delivers the convenience of high plasmid DNA yields but the additional burden of the high copy number restricts the plasmid size. Larger high copy plasmids (>30kb) are disfavoured and also prone to size reduction through deletional mutagenesis.
83:
in a cell. To ensure survival and thus the continued propagation of the plasmid, they must regulate their copy number. If a plasmid has too high of a copy number, they may excessively burden their host by occupying too much cellular machinery and using too much energy. On the other hand, too low of a
84:
copy number may result in the plasmid not being present in all of their host's progeny. Plasmids may be either low, medium or high copy number plasmids; the regulation mechanisms between low and medium copy number plasmids are different. Low copy plasmids (5 or less copies per host) require either a
279:
Plasmids can be incompatible if they share the same replication control mechanism. Under these circumstances, both plasmids contribute to the total copy number and are regulated together. They are not recognized as distinct plasmids. As such, it becomes much more likely that one of the plasmids may
165:
serves as a major plasmid-encoded inhibitor of this process whose concentration is proportional to plasmid copy number. RNA I is exactly complementary to the 5' end of the RNA II (because it is transcribed from the opposite strand of the same region of DNA as RNA II). RNA I and RNA IIled a kissing
266:
represents a simple model of an iteron plasmid. Iteron plasmids control copy number through two combined methods, suitable for low copy number stringent plasmids. One method is control of RepA synthesis. RepA is the only plasmid-encoded protein required for replication in pSC101. RepA protein
116:
Medium copy number plasmids, also called relaxed plasmids, require a system to ensure that replication is inhibited once the number of plasmids in the cell reaches a certain threshold. Relaxed plasmids are generally regulated through one of two mechanisms:
96:) is a single copy plasmid with a partitioning system encoded in an operon right next to the plasmid origin. The partitioning system interacts with the septation apparatus to ensure that each daughter receives a copy of the plasmid. Many
280:
be out-copied by the other and lost during cell division (the cell is "cured" of the plasmid). This is particularly likely with low copy number plasmids. Plasmids can also be incompatible due to shared
210:, preventing synthesis of RepA. The higher the concentration of the plasmid, the more CopA RNA is produced and the less RepA protein can be synthesized, increasing inhibition of plasmid replication.
40:
206:. CopA interacts with its RNA target in the RepA mRNA and forms a kissing complex and then a RNA-RNA duplex. The resultant double stranded RNA is cleaved by
190:
which are unique to a plasmid type. The synthesis of Rep protein is controlled in order to limit plasmid replication and therefore regulate copy number. In
194:
RepA can be transcribed from two different promoters. It is made from the first promoter until the plasmid reaches its copy number, upon which the protein
89:
455:"Copy number control of IncIalpha plasmid ColIb-P9 by competition between pseudoknot formation and antisense RNA binding at a specific RNA site"
388:
58:
199:
93:
406:"Replication control of plasmid R1: RepA synthesis is regulated by CopA RNA through inhibition of leader peptide translation"
145:
forms a stable RNA-DNA hybrid with the DNA template strand near the origin of replication, where it is then processed by
300:
Boros, I; Pósfai, G; Venetianer, P (October 1984). "High-copy-number derivatives of the plasmid cloning vector pBR322".
251:
150:
125:
binding groups. Low copy number plasmids, also called stringent plasmids, require tighter control of replication.
335:
Cesareni, G; Helmer-Citterich, M; Castagnoli, L (1991). "Control of ColE1 plasmid replication by antisense RNA".
281:
142:
92:
to ensure that each daughter receives the plasmid. For example, the F plasmid, which is the origin of BACs (
178:
Most plasmids require a plasmid-encoded protein, usually called Rep, to separate the strands of DNA at the
267:
represses its own synthesis by binding to its own promoter region and blocking transcription of itself (
179:
218:
Replication of the low-copy-number ColIb-P9 depends upon Rep, which is produced by expression of the
137:
derived plasmids, replication is primarily regulated through a small plasmid-encoded RNA called
556:
533:
484:
435:
384:
352:
317:
523:
515:
474:
466:
425:
417:
344:
309:
207:
154:
72:
158:
105:
238:
mRNA, forms an Inc RNA-mRNA duplex, and prevents formation of the pseudoknot to inhibit
528:
503:
479:
454:
421:
268:
259:
146:
100:
applications utilize mutated plasmids that replicate to high copy number. For example,
430:
405:
104:
is a medium copy number plasmid (~20 copies/cell) from which several high copy number
550:
519:
348:
313:
203:
118:
97:
85:
141:. A single promoter initiates replication in ColE1: the RNA II promoter. The RNA II
195:
255:
167:
470:
227:
191:
504:"Role of π Dimers in Coupling ("Handcuffing") of Plasmid R6K's γ ori Iterons"
379:
Snyder, Larry; Peters, Joseph E.; Henkin, Tina M.; Champness, Wendy (2013).
537:
488:
439:
356:
321:
262:
regions containing multiple (~3-7) repeats of 17-22 bp iteron sequences.
502:
Kunnimalaiyaan, S; Inman, R. B.; Rakowski, S. A.; Filutowicz, M (2005).
80:
242:
translation into Rep. In this event, replication can no longer occur.
186:) to initiate DNA replication. Rep binds to specific DNA sequences in
263:
122:
101:
198:
represses this primary promoter. RepA expression is also regulated
134:
162:
138:
166:
complex. The kissing complex is stabilized by a protein called
15:
234:
is repressed by a small antisense Inc RNA, which binds to
202:
from the secondary promoter by an antisense RNA called
36:
31:
may be too technical for most readers to understand
404:Blomberg, P; Nordström, K; Wagner, E. G. (1992).
8:
527:
478:
429:
59:Learn how and when to remove this message
43:, without removing the technical details.
374:
372:
370:
368:
366:
292:
174:R1 and ColIb-p9 Plasmids: Antisense RNA
129:ColE1 derived plasmids: Antisense RNA
41:make it understandable to non-experts
7:
226:expression requires formation of a
79:is the number of copies of a given
422:10.1002/j.1460-2075.1992.tb05333.x
88:or a toxin-antitoxin pair such as
14:
520:10.1128/JB.187.11.3779-3785.2005
94:bacterial artificial chromosomes
20:
453:Asano, K; Mizobuchi, K (1998).
381:Molecular Genetics of Bacteria
269:transcriptional autoregulation
1:
349:10.1016/0168-9525(91)90370-6
314:10.1016/0378-1119(84)90130-6
159:leading strand DNA synthesis
383:(4th ed.). ASM Press.
250:Iteron plasmids, including
573:
471:10.1093/emboj/17.17.5201
258:-related plasmids, have
508:Journal of Bacteriology
214:Col1b-P9: Antisense RNA
246:pSC101: Iteron plasmid
200:post-transcriptionally
180:origin of replication
282:partitioning systems
86:partitioning system
77:plasmid copy number
337:Trends in Genetics
514:(11): 3779–3785.
465:(17): 5201–5213.
157:uses to initiate
69:
68:
61:
564:
542:
541:
531:
499:
493:
492:
482:
459:The EMBO Journal
450:
444:
443:
433:
416:(7): 2675–2683.
410:The EMBO Journal
401:
395:
394:
376:
361:
360:
332:
326:
325:
297:
155:DNA polymerase I
73:cellular biology
64:
57:
53:
50:
44:
24:
23:
16:
572:
571:
567:
566:
565:
563:
562:
561:
547:
546:
545:
501:
500:
496:
452:
451:
447:
403:
402:
398:
391:
378:
377:
364:
334:
333:
329:
308:(1–3): 257–60.
299:
298:
294:
290:
277:
275:Incompatibility
248:
216:
176:
149:to produce the
131:
114:
106:cloning vectors
65:
54:
48:
45:
37:help improve it
34:
25:
21:
12:
11:
5:
570:
568:
560:
559:
549:
548:
544:
543:
494:
445:
396:
390:978-1555816278
389:
362:
343:(7): 230–235.
327:
291:
289:
286:
276:
273:
247:
244:
215:
212:
175:
172:
130:
127:
113:
110:
67:
66:
49:September 2015
28:
26:
19:
13:
10:
9:
6:
4:
3:
2:
569:
558:
555:
554:
552:
539:
535:
530:
525:
521:
517:
513:
509:
505:
498:
495:
490:
486:
481:
476:
472:
468:
464:
460:
456:
449:
446:
441:
437:
432:
427:
423:
419:
415:
411:
407:
400:
397:
392:
386:
382:
375:
373:
371:
369:
367:
363:
358:
354:
350:
346:
342:
338:
331:
328:
323:
319:
315:
311:
307:
303:
296:
293:
287:
285:
283:
274:
272:
270:
265:
261:
257:
253:
245:
243:
241:
237:
233:
230:in the mRNA.
229:
225:
221:
213:
211:
209:
205:
201:
197:
193:
189:
185:
181:
173:
171:
169:
164:
160:
156:
152:
148:
144:
140:
136:
128:
126:
124:
120:
119:antisense RNA
111:
109:
107:
103:
99:
98:biotechnology
95:
91:
87:
82:
78:
74:
63:
60:
52:
42:
38:
32:
29:This article
27:
18:
17:
511:
507:
497:
462:
458:
448:
413:
409:
399:
380:
340:
336:
330:
305:
301:
295:
278:
249:
239:
235:
231:
223:
219:
217:
187:
183:
177:
151:3' OH primer
132:
115:
76:
70:
55:
46:
30:
192:R1 plasmids
288:References
228:pseudoknot
143:transcript
112:Regulation
208:RNase III
90:CcdA/CcdB
557:Plasmids
551:Category
538:15901701
529:1112066
489:9724656
480:1170848
440:1378398
357:1887504
322:6096220
81:plasmid
35:Please
536:
526:
487:
477:
438:
431:556743
428:
387:
355:
320:
264:pSC101
222:gene.
147:RNaseH
123:iteron
102:pBR322
75:, the
163:RNA I
153:that
139:RNA I
135:ColE1
534:PMID
485:PMID
436:PMID
385:ISBN
353:PMID
318:PMID
302:Gene
260:oriV
254:and
240:repZ
236:repZ
232:repZ
224:repZ
220:repZ
204:CopA
196:CopB
188:oriV
184:oriV
524:PMC
516:doi
512:187
475:PMC
467:doi
426:PMC
418:doi
345:doi
310:doi
256:RK2
168:Rop
133:In
121:or
71:In
39:to
553::
532:.
522:.
510:.
506:.
483:.
473:.
463:17
461:.
457:.
434:.
424:.
414:11
412:.
408:.
365:^
351:.
339:.
316:.
306:30
304:.
284:.
161:.
540:.
518::
491:.
469::
442:.
420::
393:.
359:.
347::
341:7
324:.
312::
252:F
182:(
62:)
56:(
51:)
47:(
33:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.