Variable amino-acids positions (1)                                      
  4 8 14 18 20 37 49 84 88 110 114 115 125 129 157 164 165 173 197 223 251 257 259 264 265 266 272 273 275 278 280 281 282 283 284 285 286 287 Reference(s) Accession number(s) (3) Alternative Name (2)
LEN-2 V V T A D S S V D V T I L S R A L A A P P I L A S M H I G A L I E H W Q R Stop 4, 5 AY037780 (4), AJ635418* (5), AJ635426*(5) bla-LEN-2 
LEN-1 V Y N L Q Stop S S T G N A K 6 X04515 pre-beta-lactamase
LEN-3 ? V Y L Q ? ? ? ? ? ? ? 7 AY130286* LEN-3
LEN-4 ? L T Q ? ? ? ? ? ? ? 7 AY130287* LEN-4
LEN-5 I Y L T Stop 8, 5 AY633109 (8), AJ635422* (5), AJ635421* (5), AJ635400* (5) blaLEN-5
LEN-6 ? I L E ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 9 AY265890* blaLEN-6 allele
LEN-7 ? ? T ? ? ? ? ? ? ? ? ? ? 5 AJ635425* New LEN variant
LEN-8 ? ? V Y P L H ? ? ? ? ? ? ? ? ? ? 5 AJ635424* New LEN variant
LEN-9 ? ? V Y L ? ? ? ? ? ? ? ? ? ? 5, 12 AJ635405*, AJ635423* LEN-1
LEN-10 ? ? L T L ? ? ? ? ? ? ? ? ? ? 5, 13 AJ635419* New LEN variant
LEN-11 ? ? L A ? ? ? ? ? ? ? ? ? ? 5 AJ635417* New LEN variant
LEN-12 ? ? Y L A ? ? ? ? ? ? ? ? ? ? 5 AJ635406* New LEN variant
LEN-13 ? ? L L ? ? ? ? ? ? ? ? ? ? 5, 12 AJ635403* New LEN variant
LEN-14 ? ? Y L T C ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 9, 12 AY265889* blaLEN-5 allele
LEN-15 V Y L P A Q Stop ? ? ? ? ? ? ? 10 AF452105* LEN-type
LEN-16 Y L T Stop 11 AY743416 LEN-type
LEN-17 Y 12
LEN-18 L T V L ? ? ? ? ? ? ? ? 13 AM850908
LEN-19 Y L T V ? ? ? ? ? ? 13 AM850909
LEN-20 L T V V ? ? ? ? ? ? ? ? 13 AM850910
LEN-21 V A ? ? ? ? ? ? ? ? ? 13 AM850911
LEN-22 L P A ? ? ? ? ? ? ? ? ? 13 AM850912
LEN-23 Y L T L ? ? ? ? ? ? ? ? 13 AM850913
LEN-24 N L ? ? ? ? ? ? ? 13 AM850914
LEN-25 A L 14 Isolate 172 (LEN enzyme)
LEN-26 N Y L T M M A A M T I Q A Stop 15 Isolate 181
*: Partial sequence; ?: Not sequenced                                                                        
(1) Only variable amino-acid positions are shown. Sequences are compared with LEN-2 because LEN-1 showed a nucleotide deletion causing a frameshift with a stop codon seven amino-acid upstream of the most likely stop codon.
(2) Initial name given by authors.
(3) In case of multiple accession numbers corresponding to the same LEN-variant, only the longest sequence is shown.
(4) Chaves J., Ladona M.G., Segura C., Coira A., Reig R. and Ampurdanes C.. 2001. SHV-1 beta-lactamase is mainly a chromosomally encoded species-specific enzyme in Klebsiella pneumoniae. Antimicrob. Agents Chemother. 45:2856-2861.
(5) Haeggman S., Lofdahl S., Paauw A., Verhoef J. and Brisse S. 2004. Diversity and evolution of the class A chromosomal beta-lactamase gene in Klebsiella pneumoniae. 48:2400-8.
(6) Arakawa Y., Ohta M., Kido N., Fujii Y., Komatsu T. and Kato,N. 1986.Close evolutionary relationship between the chromosomally encoded beta-lactamase gene of Klebsiella pneumoniae and the TEM beta-lactamase gene mediated by R plasmids. FEBS Lett. 207:69-74.
(7) Paauw A., Box A.T.A., Leverstein-vanHall M.A., Verhoef J. and Fluit A.C. Submitted (10-JUL-2002).
(8) Chen S.W., Lu Y.M., Zhang R.Z., Wang S.Y., He L., Mu X.K. and Wu,W.Y. Novel beta-Lactamase, LEN-5, from a Strain of Klebsiella pneumoniae. Unpublished.
(9) Obert C.A., Goldstone C.M., Gordon D.M. and Riley M.A. Novel beta-lactamase isolated from wild Australian enteric isolates. Unpublished.
(10) Stuerenburg E., Feucht H. and Laufs R. Sequence of a beta-lactamase gene from Klebsiella pneumoniae encoding a novel LEN variant. Unpublished.
(11) Siebor E., Pechinot A., Duez J.M. and Neuwirth C. 2005. One new LEN enzyme and twonew OKP enzymes in Klebsiella pneumoniae clinical Isolates and proposed nomenclature for chromosomal beta-Lactamases of this species. Antimicrob. Agents Chemother. 49:3097-3098.
(12) Emily Curd, unpublished
(13) Mendonca N, Ferreira E, Canica M. 2009. Genetic diversity of genes encoding OKP and LEN beta-lactamases produced by clinical Klebsiella pneumoniae strains in Portugal. Diagn Microbiol Infect Dis. 63(3):334-8.
(14), Abdelgayed M. Younes Molecular Chemotherapy, Centre for Infectious Diseases, Edinburgh University, Scotland, UK
(16) Dr Hong-Xia Jiang, unpublished