116:
153:
pearl formation. This biofilm consists almost entirely of SM1 archaea making it the first biofilm found of this nature as no other biofilm with a nearly pure composition of archaea has been found. This biofilm has a highly organized structure with distances between cells being exceptionally consistent. Scientists speculate the hami are not only responsible for the strong attachments found in the biofilm formation but also this highly intricate and specific structure. It is possible that other archaeal cells possessing hami have not yet been discovered or cultured.
162:
into contact with a neighboring cell, the hami are able to entangle and produce a web like structure between the cells. This helps to form and maintain the biofilm. Hami are also used by the cells in biofilms or individually to adhere to external environmental surfaces. They have been proven to attach to substances with varying chemical compositions including those of an inorganic nature. Hami are also capable of contributing to the EPS of the cell as part of the main protein component of the EPS.
107:. Unlike fimbriae and pili, whose composition and function(s) are well defined among bacterial species, hami belong to a relatively new class of filamentous cell appendages unique to archaea. Archaeal cells may have as many as 100 hami, which are largely composed of 120 kDa subunits. Each hamus (hami plural), is helical in shape with many hook-like projections at the distal end, which are hypothesized to aid in attachment to surfaces within the environment, or in the formation of biofilms.
166:
hami were also noted to be stable over a significant pH range of 0.5-11.5. Archaea are known as extremophiles and live in extreme environments, but this capacity to remain stable over a large range of both pH and temperature makes hami very unique structures. Similarly, this lends to the possibility that archaeal hami may exist in other yet to be discovered biofilms outside of the 10 degree C temperature range and in various pH ranges.
165:
One interesting facet of these hami is that their 120 kDa protein allows them to remain stable over a broad range of temperatures. One research experiment found hami to be stable at 70 degrees C and noted the finding curious as the only currently known hami producing cells live in 10 degrees C. These
161:
Archaeal appendages serve a variety of purposes and provide the archaeal cells with multiple unique and essential abilities. Hami play a large role in cellular attachment. These appendages allow the cells to adhere to each other, as well as their surroundings. When the hami filaments of one cell come
152:
use the hamus to aid in biofilm formation. The formation of string-of-pearls communities suggests a mutual dependency for nutrient exchange, though the entirety of this unique relationship has yet to be established. Another hami producing biofilm was discovered that was dissimilar from the string
123:
Archaeal cells possessing hami appear to grow only in relatively cold aquatic environments around 10 degrees
Celsius, which could be suggestive of a particular function that has not yet been defined. One possible explanation for this observation could be the relationship archaeal cells,
591:
Anja Spang, Jimmy H. Saw, Steffen L. JΓΈrgensen, Katarzyna
Zaremba-Niedzwiedzka, Joran Martijn, Anders E.Lind, Roel van Eijk, Christa Schleper, Lionel Guy, Thijs J. G. Ettema (2015). "Complex archaea that bridge the gap between prokaryotes and eukaryotes".
804:
Perras, Alexandra K.; Wanner, Gerhard; Klingl, Andreas; Mora, Maximilian; Auerbach, Anna K.; Heinz, Veronika; Probst, Alexander J.; Huber, Harald; Rachel, Reinhard; Meck, Sandra; Moissl-Eichinger, Christine (2014-08-05).
687:
Probst, Alexander J; Holman, Hoi-Ying N; DeSantis, Todd Z; Andersen, Gary L; Birarda, Giovanni; Bechtel, Hans A; Piceno, Yvette M; Sonnleitner, Maria; Venkateswaran, Kasthuri; Moissl-Eichinger, Christine (2013-03-01).
54:
formation. This is accomplished due to their evenly placed prickles, helical structure, and barbed end. These appendages are heat and acid resistant, aiding in the cell's ability to live in extreme environments.
50:, and movement. The unique appendage was discovered at the same time as the unique community of archaea that produces them. Research into the structure of hami suggests their main function aids in attachment and
79:
that are unique to different metabolisms, scientists have dated archaea as far back as 2,500 million years. Due to oxygen being a trace element in the atmosphere at this time, archaea
144:
are filamentous bacteria that appear to form the outer shell of the pearl as well as the strings that connect these pearls together. Within the pearls, it appears the archaea
132:
a type of sulfur-oxidizing bacterium typically found within similar conditions. Hamus-bearing archaeal cells sometimes form macroscopically visible communities with
612:
99:
Archaea, much like other microorganisms, possess a variety of extracellular appendages to facilitate important functions such as motility,
247:"The unique structure of archaeal 'hami', highly complex cell appendages with nano-grappling hooks: Unique structure of archaeal 'hami'"
63:
In 1977, archaea, then known as archaebacteria, were first discovered when Carl Woese and George Fox published their findings in the
91:, while Archaea and Eukarya are considered sister lineages because they share a last common ancestor that is more recent than LUCA.
115:
88:
600:
42:). In contrast to the well-studied prokaryotic appendages pili and fimbriae, much is yet to be discovered about
356:
Ng, Sandy Y. M.; Zolghadr, Behnam; Driessen, Arnold J. M.; Albers, Sonja-Verena; Jarrell, Ken F. (2008-09-15).
104:
47:
46:
appendages such as hami. Appendages serve multiple functions for cells and are often involved in attachment,
807:"Grappling archaea: ultrastructural analyses of an uncultivated, cold-loving archaeon, and its biofilm"
246:
535:
Moissl, Christine; Rachel, Reinhard; Briegel, Ariane; Engelhardt, Harald; Huber, Robert (2005-04-01).
245:
Moissl, Christine; Rachel, Reinhard; Briegel, Ariane; Engelhardt, Harald; Huber, Robert (2005-03-07).
870:
426:
537:"The unique structure of archaeal 'hami', highly complex cell appendages with nano-grappling hooks"
295:
72:
574:
460:
329:
276:
80:
846:
828:
786:
768:
727:
709:
669:
651:
566:
558:
517:
499:
452:
444:
395:
377:
321:
268:
222:
204:
84:
690:"Tackling the minority: sulfate-reducing bacteria in an archaea-dominated subsurface biofilm"
836:
818:
776:
758:
717:
701:
659:
641:
548:
507:
491:
434:
385:
369:
311:
258:
212:
196:
83:
methanotrophy is believed to have preceded bacterial aerobic methanotrophy. When studying
430:
299:
75:
of life known today; Bacteria, Eukarya, and
Archaea. By checking the ratios of biogenic
841:
806:
781:
746:
722:
689:
664:
629:
608:
512:
479:
390:
357:
217:
184:
864:
553:
464:
263:
100:
578:
333:
280:
27:
300:"Versatile cell surface structures of archaea: Cell surface structures of archaea"
200:
23:
832:
823:
772:
713:
655:
562:
503:
448:
381:
208:
536:
850:
790:
747:"Surface Appendages of Archaea: Structure, Function, Genetics and Assembly"
731:
705:
673:
630:"Surface Appendages of Archaea: Structure, Function, Genetics and Assembly"
570:
521:
495:
456:
399:
325:
272:
226:
414:
68:
763:
646:
373:
76:
51:
43:
19:
484:
Philosophical
Transactions of the Royal Society B: Biological Sciences
316:
745:
Jarrell, Ken F.; Ding, Yan; Nair, Divya B.; Siu, Sarah (2013-01-24).
628:
Jarrell, Ken F.; Ding, Yan; Nair, Divya B.; Siu, Sarah (2013-03-01).
439:
183:
Eckburg, Paul B.; Lepp, Paul W.; Relman, David A. (February 2003).
114:
87:, Bacteria are evolved from the last universal common ancestor or
22:, one of the three domains of life, are a highly diverse group of
604:
30:
has given rise to a highly complex new appendage known as the
478:
Gribaldo, Simonetta; Brochier-Armanet, Celine (2006-06-29).
480:"The origin and evolution of Archaea: a state of the art"
148:
forms the majority of the core. Research has shown the
67:
stating that these organisms were distantly related to
119:
26:
that include a number of extremophiles. One of these
185:"Archaea and Their Potential Role in Human Disease"
65:Proceedings of the National Academy of Sciences,
8:
840:
822:
780:
762:
721:
663:
645:
552:
511:
438:
389:
315:
262:
216:
140:called a string-of-pearls. Thiothrix and
294:Chaudhury, Paushali; Quax, Tessa E. F.;
175:
71:. This revolutionized biology into the
7:
623:
621:
358:"Cell Surface Structures of Archaea"
351:
349:
347:
345:
343:
240:
238:
236:
35:
14:
554:10.1111/j.1365-2958.2005.04294.x
264:10.1111/j.1365-2958.2005.04294.x
413:Noller, Harry (January 2013).
1:
201:10.1128/IAI.71.2.591-596.2003
128:, possessing hami have with
887:
811:Frontiers in Microbiology
824:10.3389/fmicb.2014.00397
415:"Carl Woese (1928β2012)"
138:IMB1 Ξ΅- proteobacterium,
362:Journal of Bacteriology
142:IMB1 Ξ΅- proteobacterium
706:10.1038/ismej.2012.133
603::10.1038/nature14447.
541:Molecular Microbiology
496:10.1098/rstb.2006.1841
304:Molecular Microbiology
251:Molecular Microbiology
189:Infection and Immunity
157:Hami special abilities
120:
48:horizontal conjugation
118:
296:Albers, Sonja-Verena
16:Group of prokaryotes
764:10.3390/life3010086
647:10.3390/life3010086
490:(1470): 1007β1022.
431:2013Natur.493..610N
374:10.1128/JB.00546-08
59:Archaeal background
121:
85:phylogenetic trees
368:(18): 6039β6047.
317:10.1111/mmi.13889
298:(February 2018).
878:
855:
854:
844:
826:
801:
795:
794:
784:
766:
742:
736:
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694:The ISME Journal
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393:
353:
338:
337:
319:
291:
285:
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266:
242:
231:
230:
220:
180:
150:SM1 euryarchaeon
146:SM1 euryarchaeon
126:SM1 euryarchaeon
37:
886:
885:
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861:
860:
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619:
590:
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534:
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477:
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440:10.1038/493610a
412:
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341:
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182:
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177:
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113:
97:
61:
17:
12:
11:
5:
884:
882:
874:
873:
863:
862:
857:
856:
796:
737:
700:(3): 635β651.
679:
617:
584:
547:(2): 361β370.
527:
470:
405:
339:
310:(3): 298β311.
286:
257:(2): 361β370.
232:
195:(2): 591β596.
174:
173:
171:
168:
158:
155:
112:
111:Hami producers
109:
96:
93:
60:
57:
15:
13:
10:
9:
6:
4:
3:
2:
883:
872:
869:
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866:
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820:
816:
812:
808:
800:
797:
792:
788:
783:
778:
774:
770:
765:
760:
757:(1): 86β117.
756:
752:
748:
741:
738:
733:
729:
724:
719:
715:
711:
707:
703:
699:
695:
691:
683:
680:
675:
671:
666:
661:
657:
653:
648:
643:
640:(1): 86β117.
639:
635:
631:
624:
622:
618:
614:
610:
606:
602:
598:
595:
588:
585:
580:
576:
572:
568:
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560:
555:
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531:
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523:
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489:
485:
481:
474:
471:
466:
462:
458:
454:
450:
446:
441:
436:
432:
428:
425:(7434): 610.
424:
420:
416:
409:
406:
401:
397:
392:
387:
383:
379:
375:
371:
367:
363:
359:
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147:
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131:
127:
117:
110:
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106:
102:
101:cell adhesion
95:Hami function
94:
92:
90:
86:
82:
78:
74:
73:three domains
70:
66:
58:
56:
53:
49:
45:
41:
33:
29:
28:extremophiles
25:
21:
814:
810:
799:
754:
750:
740:
697:
693:
682:
637:
633:
596:
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530:
487:
483:
473:
422:
418:
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365:
361:
307:
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289:
254:
250:
192:
188:
178:
164:
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149:
145:
141:
137:
133:
129:
125:
122:
105:DNA transfer
98:
64:
62:
39:
31:
18:
871:Prokaryotes
611:: 4444528.
599:: 173β179.
24:prokaryotes
615:0028-0836.
607:25945739.
170:References
130:Thiothrix,
833:1664-302X
773:2075-1729
714:1751-7362
656:2075-1729
563:0950-382X
504:0962-8436
465:205076152
449:1476-4687
382:0021-9193
209:0019-9567
134:Thiothrix
81:anaerobes
865:Category
851:25140167
791:25371333
732:23178669
674:25371333
579:31690026
571:15813730
522:16754611
457:23364736
400:18621894
334:19045028
326:29194812
281:31690026
273:15813730
227:12540534
77:isotopes
69:bacteria
44:archaeal
842:4122167
817:: 397.
782:4187195
723:3578563
665:4187195
513:1578729
427:Bibcode
391:2546794
52:biofilm
20:Archaea
849:
839:
831:
789:
779:
771:
730:
720:
712:
672:
662:
654:
594:Nature
577:
569:
561:
520:
510:
502:
463:
455:
447:
419:Nature
398:
388:
380:
332:
324:
279:
271:
225:
218:145348
215:
207:
103:, and
575:S2CID
461:S2CID
330:S2CID
277:S2CID
32:hamus
847:PMID
829:ISSN
787:PMID
769:ISSN
751:Life
728:PMID
710:ISSN
670:PMID
652:ISSN
634:Life
613:ISSN
605:PMID
567:PMID
559:ISSN
518:PMID
500:ISSN
453:PMID
445:ISSN
396:PMID
378:ISSN
322:PMID
269:PMID
223:PMID
205:ISSN
89:LUCA
40:hami
837:PMC
819:doi
777:PMC
759:doi
718:PMC
702:doi
660:PMC
642:doi
609:PMC
601:DOI
597:521
549:doi
508:PMC
492:doi
488:361
435:doi
423:493
386:PMC
370:doi
366:190
312:doi
308:107
259:doi
213:PMC
197:doi
136:or
36:pl.
867::
845:.
835:.
827:.
813:.
809:.
785:.
775:.
767:.
753:.
749:.
726:.
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708:.
696:.
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668:.
658:.
650:.
636:.
632:.
620:^
573:.
565:.
557:.
545:56
543:.
539:.
516:.
506:.
498:.
486:.
482:.
459:.
451:.
443:.
433:.
421:.
417:.
394:.
384:.
376:.
364:.
360:.
342:^
328:.
320:.
306:.
302:.
275:.
267:.
255:56
253:.
249:.
235:^
221:.
211:.
203:.
193:71
191:.
187:.
38::
853:.
821::
815:5
793:.
761::
755:3
734:.
704::
698:7
676:.
644::
638:3
581:.
551::
524:.
494::
467:.
437::
429::
402:.
372::
336:.
314::
283:.
261::
229:.
199::
34:(
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