Here's another one: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2258702/...Second, as predicted, sequence variation in the N-terminal region of the SL-CoV S protein rendered it incapable of using ACE2 as a receptor for cell entry. However, the ACE2-binding activity of SL-CoVs was easily acquired by the replacement of a relatively small sequence segment of the S protein from the SARS-CoV S sequence, highlighting the potential dangers posed by this diverse group of viruses in bats. It is now well documented that bat species, including horseshoe bats, can be infected by different CoVs. Coinfection by different CoVs in an individual bat has also been observed (26, 29, 39). Knowing the capability of different CoVs to recombine both in the laboratory (2, 14, 15, 32) and in nature (22, 41, 44), the possibility that SL-CoVs may gain the ability to infect human cells by acquiring S sequences competent for binding to ACE2 or other surface proteins of human cells can be readily envisaged.