Exosporium: Difference between revisions
m Opabinia regalis moved page Exosprium to Exosporium: typo |
cleanup, remove close paraphrasing |
||
| Line 1: | Line 1: | ||
{{incomplete}} |
|||
{{Multiple issues| |
|||
{{Orphan|date=April 2015}} |
|||
{{technical|date=April 2015}} |
|||
}} |
|||
The '''exosporium''' is the outer surface layer of mature [[spores]]. |
The '''exosporium''' is the outer surface layer of mature [[spores]]. In plant spores it is also referred to as the [[exine]]. Some [[bacteria]] also produce [[endospores]] with an exosporium, of which the most commonly studied are ''[[Bacillus]]'' species, particularly ''[[Bacillus cereus]]'' and the [[anthrax]]-causing bacterium ''[[Bacillus anthracis]]''. The exosporium is the portion of the spore that interacts with the [[Environment (biophysical)|environment]] or [[host (biology)|host organism]], and may contain spore [[antigen]]s.<ref name="redmond">{{cite journal|last1=Redmond|first1=C.|title=Identification of proteins in the exosporium of Bacillus anthracis|journal=Microbiology|date=2004|volume=150|issue=2|pages=355–363|doi=10.1099/mic.0.26681-0|url=http://mic.sgmjournals.org/content/150/2/355.long}}</ref> |
||
==In ''B. anthracis''== |
|||
| ⚫ | [[Salt]] and [[detergent]] washing of exosporium fragments |
||
| ⚫ | [[Salt]] and [[detergent]] washing of exosporium fragments can identify [[protein]]s that are likely to represent structural or integral exosporium proteins. Seven proteins have been identified in washed exosporium: [[alanine racemase]], [[inosine]] [[hydrolase]], ExsF, CotY, ExsY, CotB, and a novel protein, ExsK. CotY, ExsY and CotB are [[homologue]]s of [[Bacillus subtilis]] outer spore coat proteins, but ExsF and ExsK are specific to B. anthracis and other members of the [[Bacillus cereus]] group.<ref name="redmond" /> |
||
The exosporium protein ΔywdL has a more fragile exosporium, subject to damage on repeated [[freeze-thaw]]ing. YwdL is important for formation of a robust exosporium, but is not required to maintain the [[crystalline]] assembly within the [[basal layer]] or for attachment of the hairy nap structure. ΔywdL spores are unable to [[germination|germinate]] in response to CaDPA. This protein causes altered germination properties with a [[phenotype]] that confirms the expected defect in localization of the [[cortex (anatomy)|cortex]] lytic [[enzyme]] CwlJ in the [[skin|coat]].<ref>{{cite journal|last1=Redmond|first1=C.|title=Identification of proteins in the exosporium of Bacillus anthracis|journal=Microbiology|date=2004|volume=150|issue=2|pages=355–363|doi=10.1099/mic.0.26681-0|url=http://mic.sgmjournals.org/content/150/2/355.long}}</ref><ref>{{cite journal|last1=Terry|first1=Cassandra|last2=Shepherd|first2=Andrew|last3=Radford|first3=David S.|last4=Moir|first4=Anne|last5=Bullough|first5=Per A.|title=YwdL in Bacillus cereus: Its Role in Germination and Exosporium Structure|journal=PLoS ONE|date=2011|volume=6|issue=8|pages=e23801|doi=10.1371/journal.pone.0023801|url=http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0023801}}</ref> |
|||
==In ''B. cereus''== |
|||
The protein ywdL has been identified in ''B. cereus'' as important for exosporium formation. In the absence of the ywdL gene, a fragile and easily damaged exosporium is formed, which can be damaged by mechanical disruption such as [[freeze-thaw]] cycles. However, ywdL is not required to maintain the internal organization of the exosporium. ΔywdL spores have abnormal [[germination]] properties, such as the inability to respond to standard chemical means of inducing germination by treatment with [[Dipicolinic acid|calcium dipicolinate]].<ref>{{cite journal|last1=Terry|first1=Cassandra|last2=Shepherd|first2=Andrew|last3=Radford|first3=David S.|last4=Moir|first4=Anne|last5=Bullough|first5=Per A.|title=YwdL in Bacillus cereus: Its Role in Germination and Exosporium Structure|journal=PLoS ONE|date=2011|volume=6|issue=8|pages=e23801|doi=10.1371/journal.pone.0023801|url=http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0023801}}</ref> |
|||
==References== |
==References== |
||
{{reflist}} |
{{reflist}} |
||
{{microbiology-stub}} |
|||
{{uncategorized|date=April 2015}} |
|||
[[Category:Microbiology]] |
|||
Revision as of 19:15, 15 April 2015
 | This article is missing information about Error: you must specify what information is missing.. |
The exosporium is the outer surface layer of mature spores. In plant spores it is also referred to as the exine. Some bacteria also produce endospores with an exosporium, of which the most commonly studied are Bacillus species, particularly Bacillus cereus and the anthrax-causing bacterium Bacillus anthracis. The exosporium is the portion of the spore that interacts with the environment or host organism, and may contain spore antigens.[1]
In B. anthracis
Salt and detergent washing of exosporium fragments can identify proteins that are likely to represent structural or integral exosporium proteins. Seven proteins have been identified in washed exosporium: alanine racemase, inosine hydrolase, ExsF, CotY, ExsY, CotB, and a novel protein, ExsK. CotY, ExsY and CotB are homologues of Bacillus subtilis outer spore coat proteins, but ExsF and ExsK are specific to B. anthracis and other members of the Bacillus cereus group.[1]
In B. cereus
The protein ywdL has been identified in B. cereus as important for exosporium formation. In the absence of the ywdL gene, a fragile and easily damaged exosporium is formed, which can be damaged by mechanical disruption such as freeze-thaw cycles. However, ywdL is not required to maintain the internal organization of the exosporium. ΔywdL spores have abnormal germination properties, such as the inability to respond to standard chemical means of inducing germination by treatment with calcium dipicolinate.[2]
References
- ^ a b Redmond, C. (2004). "Identification of proteins in the exosporium of Bacillus anthracis". Microbiology. 150 (2): 355–363. doi:10.1099/mic.0.26681-0.
- ^ Terry, Cassandra; Shepherd, Andrew; Radford, David S.; Moir, Anne; Bullough, Per A. (2011). "YwdL in Bacillus cereus: Its Role in Germination and Exosporium Structure". PLoS ONE. 6 (8): e23801. doi:10.1371/journal.pone.0023801.
{{cite journal}}: CS1 maint: unflagged free DOI (link)
 | This microbiology-related article is a stub. You can help Wikipedia by expanding it. |